Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
Network Working Group Jonathan P. Lang, Editor
Internet Draft
Expiration Date: December 2002
June 2002
Link Management Protocol (LMP)
draft-ietf-ccamp-lmp-04.txt
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026 [RFC2026].
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Abstract
Optical networks are being developed to include photonic switches,
optical crossconnects, and routers that are configured with control
channels and data links. Furthermore, multiple data links may be
combined to form a single traffic engineering (TE) link for routing
purposes. This draft specifies a link management protocol (LMP) that
runs between neighboring nodes and is used to manage TE links.
Specifically, LMP will be used to maintain control channel
connectivity, verify the physical connectivity of the data-bearing
channels, correlate the link property information, suppress
downstream alarms, and localize link failures for
protection/restoration purposes in both opaque and transparent
networks.
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Table of Contents
1 Introduction ................................................ 4
2 LMP Overview ................................................ 5
3 Control Channel Management ................................... 7
3.1 Parameter Negotiation ................................... 8
3.2 Hello Protocol ........................................... 9
3.2.1 Hello Parameter Negotiation ....................... 9
3.2.2 Fast Keep-alive .................................. 10
3.2.3 Control Channel Down ............................. 11
3.2.4 Degraded (DEG) State ............................. 11
4 Link Property Correlation ................................... 11
5 Verifying Link Connectivity ................................. 13
5.1 Example of Link Connectivity Verification ............... 16
6 Fault Management ............................................ 17
6.1 Fault Detection ......................................... 17
6.2 Fault Localization Procedure ............................ 18
6.3 Examples of Fault Localization .......................... 18
6.4 Channel Activation Indication ........................... 19
6.5 Channel Deactivation Indication ......................... 20
7 Message_Id Usage ............................................ 20
8 Graceful Restart ............................................ 21
9 Addressing .................................................. 22
10 Exponential Back-off Procedures ............................. 23
10.1 Operation.................................................. 23
10.2 Retransmission Algorithm .................................. 23
11 IANA Considerations ......................................... 24
12 LMP Finite State Machines ................................... 24
12.1 Control Channel FSM .................................... 24
12.1.1 Control Channel States .......................... 24
12.1.2 Control Channel Events .......................... 25
12.1.3 Control Channel FSM Description ................. 28
12.2 TE Link FSM ............................................ 29
12.2.1 TE link States .................................. 29
12.2.2 TE link Events .................................. 29
12.2.3 TE link FSM Description ......................... 30
12.3 Data Link FSM .......................................... 30
12.3.1 Data Link States ................................ 31
12.3.2 Data Link Events ................................ 31
12.3.3 Active Data Link FSM Description ................ 33
12.3.4 Passive Data Link FSM Description ............... 34
13 LMP Message Formats ......................................... 35
13.1 Common Header .......................................... 35
13.2 LMP Object Format ...................................... 36
13.3 Parameter Negotiation .................................. 37
13.4 Hello .................................................. 39
13.5 Link Verification ...................................... 39
13.6 Link Summary ........................................... 43
13.7 Fault Management ....................................... 44
14 LMP Object Definitions ...................................... 45
15 Security Conderations ....................................... 63
16 Intellectual Property Considerations ........................ 63
17 References .................................................. 63
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18 Acknowledgments ............................................. 64
19 Contributors ................................................ 65
20 Contact Address ............................................. 65
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Changes from previous version:
o Editorial changes.
o Changed LMP from running directly over IP to running over UDP.
o Added Section describing exponential back-off procedures.
o Added suggested values for timers.
o Merged the LOCAL/REMOTE Id classes into single class.
o Merged the MESSAGE_ID/MESSAGE_ID_ACK classes into single class.
o Removed the MD5 security option.
1. Introduction
Optical networks are being developed with photonic switches (PXCs),
optical crossconnects (OXCs), routers, switches, DWDM systems, and
add-drop multiplexors (ADMs) that use a common control plane [e.g.,
Generalized MPLS (GMPLS)] to dynamically allocate resources and to
provide network survivability using protection and restoration
techniques. A pair of nodes (e.g., two PXCs) may be connected by
thousands of fibers, and each fiber may be used to transmit multiple
wavelengths if DWDM is used. Furthermore, multiple fibers and/or
multiple wavelengths may be combined into a single traffic-
engineering (TE) link for routing purposes. To enable communication
between nodes for routing, signaling, and link management, control
channels must be established between the node pair; however, the
interface over which the control messages are sent/received may not
be the same interface over which the data flows. This draft
specifies a link management protocol (LMP) that runs between
neighboring nodes and is used to manage TE links.
In this draft, OXC is used to refer to all categories of optical
crossconnects irrespective of the internal switching fabric.
Furthermore, a distinction is made between crossconnects that
require opto-electronic conversion, called digital crossconnects
(DXCs), and those that are all-optical, called photonic switches or
photonic crossconnects (PXCs) û often referred to as pure
crossconnects [LAMBDA] because their transparent nature introduces
new restrictions for monitoring and managing the data links. LMP can
be used for any type of node, enhancing the functionality of
traditional DXCs and routers, while enabling PXCs and DWDMs to
intelligently interoperate in heterogeneous optical networks.
In GMPLS, the control channels between two adjacent nodes are no
longer required to use the same physical medium as the data-bearing
links between those nodes. For example, a control channel could use
a separate wavelength or fiber, an Ethernet link, an IP tunnel
through a separate management network, or a multi-hop IP network. A
consequence of allowing the control channel(s) between two nodes to
be physically diverse from the associated data links is that the
health of a control channel does not necessarily correlate to the
health of the data links, and vice-versa. Therefore, a clean
separation between the fate of the control channel and data-bearing
links must be made. New mechanisms must be developed to manage the
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data-bearing links, both in terms of link provisioning and fault
management.
For the purposes of this document, a data-bearing link may be either
a "port" or a "component link" depending on its multiplexing
capability; component links are multiplex capable, whereas ports are
not multiplex capable. This distinction is important since the
management of such links (including, for example, resource
allocation, label assignment, and their physical verification) is
different based on their multiplexing capability. For example, a
SONET crossconnect with OC-192 interfaces may be able to demultiplex
the OC-192 stream into four OC-48 streams. If multiple interfaces
are grouped together into a single TE link using link bundling
[BUNDLE], then the link resources must be identified using three
levels: TE link Id, component interface Id, and timeslot label.
Resource allocation happens at the lowest level (timeslots), but
physical connectivity happens at the component link level. As
another example, consider the case where a PXC transparently
switches OC-192 lightpaths. If multiple interfaces are once again
grouped together into a single TE link, then link bundling [BUNDLE]
is not required and only two levels of identification are required:
TE link Id and port Id. In this case, both resource allocation and
physical connectivity happen at the lowest level (i.e. port level).
To ensure interworking between data links with different
multiplexing capabilities, LMP capable devices SHOULD allow sub-
channels of a component link to be locally configured as (logical)
data links. For example, if a Router with 4 OC-48 interfaces is
connected through a 4:1 MUX to an OXC with OC-192c interfaces, the
OXC SHOULD be able to configure each OC-48 sub-channel as a data
link.
LMP is designed to support aggregation of one or more data-bearing
links into a TE link (either ports into TE links, or component links
into TE links). The purpose of forming a TE link is to group/map the
information about certain physical resources (and their properties)
into the information that is used by Constrained SPF for the purpose
of path computation, and by GMPLS signaling.
2. LMP Overview
The two core procedures of LMP are control channel management and
link property correlation. Control channel management is used to
establish and maintain control channels between adjacent nodes. This
is done using a Config message exchange and a fast keep-alive
mechanism between the nodes. The latter is required if lower-level
mechanisms are not available to detect control channel failures.
Link property correlation is used to synchronize the TE link
properties and verify the TE link configuration.
LMP requires that a pair of nodes have at least one active bi-
directional control channel between them. Each direction of the
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control channel is identified by a control channel id (CCId), and
the two directions are coupled together using the LMP Config message
exchange. All LMP messages are IP encoded [except in some cases, the
Test Message which may be limited by the transport mechanism for in-
band messaging]. The link level encoding of the control channel is
outside the scope of this document.
An "LMP adjacency" is formed between two nodes when at least one bi-
directional control channel is established between them. Multiple
control channels may be active simultaneously for each adjacency;
control channel parameters, however, MUST be individually negotiated
for each control channel. If the LMP fast keep-alive is used over a
control channel, LMP Hello messages MUST be exchanged over the
control channel. Other LMP messages MAY be transmitted over any of
the active control channels between a pair of adjacent nodes. One or
more active control channels may be grouped into a logical control
channel for signaling, routing, and link property correlation
purposes.
The link property correlation function of LMP is designed to
aggregate multiple data links (ports or component links) into a TE
link and to synchronize the properties of the TE link. As part of
the link property correlation function, a LinkSummary message
exchange is defined. The LinkSummary message includes the local and
remote TE Link Ids, a list of all data links that comprise the TE
link, and various link properties. A LinkSummaryAck or
LinkSummaryNack message MUST be sent in response to the receipt of a
LinkSummary message indicating agreement or disagreement on the link
properties.
LMP messages are transmitted reliably using Message Ids and
retransmissions. Message Ids are carried in MESSAGE_ID objects. No
more than one MESSAGE_ID object may be included in an LMP message.
For control channel specific messages, the Message Id is within the
scope of the control channel over which the message is sent. For TE
link specific messages, the Message Id is within the scope of the
LMP adjacency. The value of the Message Id is monotonically
increasing and only decreases when the value wraps.
In this draft, two additional LMP procedures are defined: link
connectivity verification and fault management. These procedures are
particularly useful when the control channels are physically diverse
from the data-bearing links. Link connectivity verification is used
for data plane discovery, Interface Id exchange (Interface Ids are
used in GMPLS signaling, either as Port labels or Component
Interface Ids, depending on the configuration), and physical
connectivity verification. This is done by sending Test messages in-
band over the data-bearing links and TestStatus messages back over
the control channel. Note that the Test message is the only LMP
message that must be transmitted over the data-bearing link. The
ChannelStatus message exchange is used between adjacent nodes for
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both the suppression of downstream alarms and the localization of
faults for protection and restoration.
For LMP link connectivity verification using a PXC, the Test message
is generated and terminated by opaque test units that may be shared
among multiple ports. Opaque test units are needed since the PXC
ports are transparent. The LMP link connectivity verification
procedure is coordinated using a BeginVerify message exchange over a
control channel. To support various degrees of transparency (e.g.,
examining overhead bytes, terminating the payload, etc.), and hence,
different mechanisms to transport the Test messages, a Verify
Transport Mechanism is included in the BeginVerify and
BeginVerifyAck messages. Note that there is no requirement that all
data-bearing links must be terminated simultaneously, but at a
minimum, it must be possible to terminate them one at a time. There
is also no requirement that the control channel and TE link use the
same physical medium; however, the control channel MUST terminate on
the same two nodes that the TE link spans. Since the BeginVerify
message exchange coordinates the Test procedure, it also naturally
coordinates the transition of the data links between opaque and
transparent mode.
The LMP fault management procedure is based on a ChannelStatus
exchange using the following messages: ChannelStatus,
ChannelStatusAck, ChannelStatusRequest, and ChannelStatusResponse.
The ChannelStatus message is sent unsolicitated and is used to
notify an LMP neighbor about the status of one or more data channels
of a TE link. The ChannelStatusAck message is used to acknowledge
receipt of the ChannelStatus message. The ChannelStatusRequest
message is used to query an LMP neighbor for the status of one or
more data channels of a TE Link. The ChannelStatusResponse message
is used to acknowledge receipt of the ChannelStatusRequest message
and indicate the states of the queried data links.
3. Control Channel Management
To initiate an LMP adjacency between two nodes, one or more bi-
directional control channels MUST be activated. The control channels
can be used to exchange control-plane information such as link
provisioning and fault management information (implemented using a
messaging protocol such as LMP, proposed in this draft), path
management and label distribution information (implemented using a
signaling protocol such as RSVP-TE [RFC3209] or CR-LDP [RFC3219]),
and network topology and state distribution information (implemented
using traffic engineering extensions of protocols such as OSPF
[OSPF-TE] and IS-IS [ISIS-TE]).
For the purposes of LMP, the exact implementation of the control
channel is not specified; it could be, for example, a separate
wavelength or fiber, an Ethernet link, an IP tunnel through a
separate management network, or the overhead bytes of a data-bearing
link. Rather, a node-wide unique 32-bit non-zero integer control
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channel identifier (CCId) is assigned at each end of the control
channel. This identifier comes from the same space as the unnumbered
interface Id. Furthermore, LMP packets are run over UDP with an LMP
port number. Thus, the link level encoding of the control channel is
not part of the LMP specification.
To establish a control channel, the destination IP address on the
far end of the control channel must be known. This knowledge may be
manually configured or automatically discovered. Note that for in-
band signaling, a control channel could be explicitly configured on
a particular data-bearing link. In this case, the Config message
exchange can be used to dynamically learn the IP address on the far
end of the control channel. This is done by sending the Config
message to the Multicast address (224.0.0.1). The ConfigAck and
ConfigNack messages MUST be sent to the source IP address found in
the IP header of the received Config message.
Control channels exist independently of TE links and multiple
control channels may be active simultaneously between a pair of
nodes. Individual control channels can be realized in different
ways; one might be implemented in-fiber while another one may be
implemented out-of-fiber. As such, control channel parameters MUST
be negotiated over each individual control channel, and LMP Hello
packets MUST be exchanged over each control channel to maintain LMP
connectivity if other mechanisms are not available. Since control
channels are electrically terminated at each node, it may be
possible to detect control channel failures using lower layers
(e.g., SONET/SDH).
There are four LMP messages that are used to manage individual
control channels. They are the Config, ConfigAck, ConfigNack, and
Hello messages. These messages MUST be transmitted on the channel to
which they refer. All other LMP messages may be transmitted over any
of the active control channels between a pair of LMP adjacent nodes.
In order to maintain an LMP adjacency, it is necessary to have at
least one active control channel between a pair of adjacent nodes
(recall that multiple control channels can be active simultaneously
between a pair of nodes). In the event of a control channel failure,
alternate active control channels can be used and it may be possible
to activate additional control channels as described below.
3.1. Parameter Negotiation
Control channel activation begins with a parameter negotiation
exchange using Config, ConfigAck, and ConfigNack messages. The
contents of these messages are built using LMP objects, which can be
either negotiable or non-negotiable (identified by the N bit in the
object header). Negotiable objects can be used to let LMP peers
agree on certain values. Non-negotiable objects are used for the
announcement of specific values that do not need, or do not allow,
negotiation.
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To activate a control channel, a Config message MUST be transmitted
to the remote node, and in response, a ConfigAck message MUST be
received at the local node. The Config message contains the Local
Control Channel ID (CC_ID), the senderÆs Node ID, a MessageId for
reliable messaging, and a CONFIG object. It is possible that both
the local and remote nodes initiate the configuration procedure at
the same time. To avoid ambiguities, the node with the higher Node
Id wins the contention; the node with the lower Node Id MUST stop
transmitting the Config message and respond to the Config message it
received.
The ConfigAck message is used to acknowledge receipt of the Config
message and express agreement on ALL of the configured parameters
(both negotiable and non-negotiable).
The ConfigNack message is used to acknowledge receipt of the Config
message, indicate which (if any) non-negotiable CONFIG objects are
unacceptable, and propose alternate values for the negotiable
parameters.
If a node receives a ConfigNack message with acceptable alternate
values for negotiable parameters, the node SHOULD transmit a Config
message using these values for those parameters.
If a node receives a ConfigNack message with unacceptable alternate
values, the node MAY continue to retransmit Config messages. Note
that the problem may be solved by an operator changing parameters.
In the case where multiple control channels use the same physical
interface, the parameter negotiation exchange is performed for each
control channel. The various LMP parameter negotiation messages are
associated with their corresponding control channels by their node-
wide unique identifiers (CCIds).
3.2. Hello Protocol
Once a control channel is activated between two adjacent nodes, the
LMP Hello protocol can be used to maintain control channel
connectivity between the nodes and to detect control channel
failures. The LMP Hello protocol is intended to be a lightweight
keep-alive mechanism that will react to control channel failures
rapidly so that IGP Hellos are not lost and the associated link-
state adjacencies are not removed unnecessarily.
3.2.1. Hello Parameter Negotiation
Before sending Hello messages, the HelloInterval and
HelloDeadInterval parameters MUST be agreed upon by the local and
remote nodes. These parameters are exchanged in the Config message.
The HelloInterval indicates how frequently LMP Hello messages will
be sent, and is measured in milliseconds (ms). For example, if the
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value were 150, then the transmitting node would send the Hello
message at least every 150ms. The HelloDeadInterval indicates how
long a device should wait to receive a Hello message before
declaring a control channel dead, and is measured in milliseconds
(ms). The HelloDeadInterval MUST be greater than the HelloInterval,
and SHOULD be at least 3 times the value of HelloInterval.
Suggested default values for the HelloInterval is 5 ms and for the
HelloDeadInterval is 18 ms.
If the fast keep-alive mechanism of LMP is not used, the
HelloInterval and HelloDeadInterval parameters MUST be set to zero.
When a node has either sent or received a ConfigAck message, it may
begin sending Hello messages. Once it has sent a Hello message and
received a valid Hello message (i.e., with expected sequence
numbers; see Section 3.2.2), the control channel moves to the UP
state. (It is also possible to move to the UP state without sending
Hellos if other methods are used to indicate bi-directional control-
channel connectivity.) If, however, a node receives a ConfigNack
message instead of a ConfigAck message, the node MUST not send Hello
messages and the control channel SHOULD NOT move to the UP state.
See Section 12.1 for the complete control channel FSM.
3.2.2. Fast Keep-alive
Each Hello message contains two sequence numbers: the first sequence
number (TxSeqNum) is the sequence number for the Hello message being
sent and the second sequence number (RcvSeqNum) is the sequence
number of the last Hello message received from the adjacent node
over this control channel. Each node increments its sequence number
when it sees its current sequence number reflected in Hellos
received from its peer. The sequence numbers start at 1 and wrap
around back to 2; 0 is used in the RcvSeqNum to indicate that a
Hello has not yet been seen.
Under normal operation, the difference between the RcvSeqNum in a
Hello message that is received and the local TxSeqNum that is
generated will be at most 1. This difference can be more than one
only when a control channel restarts or when the values wrap.
Note that the 32-bit sequence numbers MAY wrap. The following
expression may be used to test if a newly received TxSeqNum value is
less than a previously received value:
If ((int) old_id û (int) new_id > 0) {
New value is less than old value;
}
Having sequence numbers in the Hello messages allows each node to
verify that its peer is receiving its Hello messages. By including
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the RcvSeqNum in Hello packets, the local node will know which Hello
packets the remote node has received.
The following example illustrates how the sequence numbers operate.
Note that only the operation at one node is shown, and alternative
scenarios are possible:
1) After completing the configuration stage, Node A sends Hello
messages to Node B with {TxSeqNum=1;RcvSeqNum=0}.
2) When Node A receives a Hello from Node B with
{TxSeqNum=1;RcvSeqNum=1}, it sends Hellos to Node B with
{TxSeqNum=2;RcvSeqNum=1}.
3) When Node A receives a Hello from Node B with
{TxSeqNum=2;RcvSeqNum=2}, it sends Hellos to Node B with
{TxSeqNum=3;RcvSeqNum=2}.
3.2.3. Control Channel Down
To allow bringing a control channel DOWN gracefully for
administration purposes, a ControlChannelDown flag is available in
the Common Header of LMP packets. When data links are still in use
between a pair of nodes, a control channel SHOULD only be taken down
administratively when there are other active control channels that
can be used to manage the data links.
When bringing a control channel DOWN administratively, a node MUST
set the ControlChannelDown flag in all LMP messages sent over the
control channel. The node that initiated the control channel DOWN
procedure may stop sending Hello messages after HelloDeadInterval
seconds have passed, or if it receives an LMP message over the same
control channel with the ControlChannelDown flag set.
When a node receives an LMP packet with the ControlChannelDown flag
set, it SHOULD send a Hello message with the ControlChannelDown flag
set and move the control channel to the Down state.
3.2.4. Degraded State
A consequence of allowing the control channels to be physically
diverse from the associated data links is that there may not be any
active control channels available while the data links are still in
use. For many applications, it is unacceptable to tear down a link
that is carrying user traffic simply because the control channel is
no longer available; however, the traffic that is using the data
links may no longer be guaranteed the same level of service. Hence
the TE link is in a Degraded state.
When a TE link is in the Degraded state, routing and signaling
SHOULD be notified so that new connections are not accepted and the
TE link is advertised with no unreserved resources.
4. Link Property Correlation
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As part of LMP, a link property correlation exchange is defined for
TE links using the LinkSummary, LinkSummaryAck, and LinkSummaryNack
messages. The contents of these messages are built using LMP
objects, which can be either negotiable or non-negotiable
(identified by the N flag in the object header). Negotiable objects
can be used to let both sides agree on certain link parameters. Non-
negotiable objects are used for announcement of specific values that
do not need, or do not allow, negotiation.
Each TE link has an identifier (Link_Id) that is assigned at each
end of the link. These identifiers MUST be the same type (i.e, IPv4,
IPv6, unnumbered) at both ends. If a LinkSummary message is received
with different local and remote TE link types, then a
LinkSummaryNack message MUST be sent with Error Code "Bad TE Link
Object". Similarly, each data link is assigned an identifier
(Interface_Id) at each end. These identifiers MUST also be the same
type at both ends. If a LinkSummary message is received with
different local and remote Interface Id types then a LinkSummaryNack
message MUST be sent with Error Code "Bad Data Link Object".
Link property correlation SHOULD be done before the link is brought
up and MAY be done at any time a link is UP and not in the
Verification process.
The LinkSummary message is used to verify for consistency the TE and
data bearing link information on both sides. Link Summary messages
are also used to aggregate multiple data links (either ports or
component links) into a TE link; exchange, correlate (to determine
inconsistencies), or change TE link parameters; and exchange,
correlate (to determine inconsistencies), or change Interface Ids
(used either Port Ids or Component Interface Ids).
The LinkSummary message includes a TE_LINK object followed by one or
more DATA_LINK objects. The TE_LINK object identifies the TE link's
local and remote Link Id and indicates support for fault management
and link verification procedures for that TE link. The DATA_LINK
objects are used to characterize the data links that comprise the TE
link. These objects include the local and remote Interface Ids, and
may include one or more sub-objects further describing the
properties of the data links.
If the LinkSummary message is received from a remote node and the
Interface Id mappings match those that are stored locally, then the
two nodes have agreement on the Verification procedure (see Section
5) and data link configuration. If the verification procedure is not
used, the LinkSummary message can be used to verify agreement on
manual configuration.
The LinkSummaryAck message is used to signal agreement on the
Interface Id mappings and link property definitions. Otherwise, a
LinkSummaryNack message MUST be transmitted, indicating which
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Interface mappings are not correct and/or which link properties are
not accepted. If a LinkSummaryNack message indicates that the
Interface Id mappings are not correct and the link verification
procedure is enabled, the link verification process SHOULD be
repeated for all mismatched free data links; if an allocated data
link has a mapping mismatch, it SHOULD be flagged and verified when
it becomes free. If a LinkSummaryNack message includes negotiable
parameters, then acceptable values for those parameters MUST be
included. If a LinkSummaryNack message is received and includes
negotiable parameters, then the initiator of the LinkSummary message
SHOULD send a new LinkSummary message. The new LinkSummary message
SHOULD include new values for the negotiable parameters. These
values SHOULD take into account the acceptable values received in
the LinkSummaryNack message.
It is possible that the LinkSummary message could grow quite large
due to the number of DATA LINK objects. Since the LinkSummary
message is IP encoded, normal IP fragmentation should be used if the
resulting PDU exceeds the MTU.
5. Verifying Link Connectivity
In this section, an optional procedure is described that may be used
to verify the physical connectivity of the data-bearing links and
dynamically learn (i.e., discover) the TE link and Interface ID
associations. The procedure SHOULD be done when establishing a TE
link, and subsequently, on a periodic basis for all unallocated
(free) data links of the TE link.
Support for this procedure is indicated by setting the "Link
Verification Supported" flag in the TE_LINK object of the
LinkSummary message.
If a BeginVerify message is received and link verification is not
supported for the TE link, then a BeginVerifyNack message MUST be
transmitted with Error Code indicating "Link Verification Procedure
not supported for this TE Link."
A unique characteristic of all-optical switches is that the data-
bearing links are transparent when allocated to user traffic. This
characteristic poses a challenge for validating the connectivity of
the data links. For example, shining unmodulated light through a
link may not result in received light at the next switch because
there may be terminating (or opaque) elements, such as DWDM
equipment, between the PXCs. Therefore, to ensure proper
verification of data link connectivity, it is required that until
the links are allocated for user traffic, they must be opaque. To
support various degrees of opaqueness (e.g., examining overhead
bytes, terminating the payload, etc.), and hence different
mechanisms to transport the Test messages, a Verify Transport
Mechanism field is included in the BeginVerify and BeginVerifyAck
messages.
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There is no requirement that all data links be terminated
simultaneously, but at a minimum, the data links MUST be able to be
terminated one at a time. Furthermore, for the link verification
procedure it is assumed that the nodal architecture is designed so
that messages can be sent and received over any data link. Note that
this requirement is trivial for DXCs (and OEO devices in general)
since each data link is terminated and processed electronically
before being forwarded to the next OEO device, but that in PXCs (and
transparent devices in general) this is an additional requirement.
To interconnect two nodes, a TE link is defined between them, and at
a minimum, there MUST be at least one active control channel between
the nodes. For link verification, a TE link MUST include at least
one data link.
Once a control channel has been established between the two nodes,
data link connectivity can be verified by exchanging Test messages
over each of the data links specified in the TE link. It should be
noted that all LMP messages except the Test message are exchanged
over the control channels and that Hello messages continue to be
exchanged over each control channel during the data link
verification process. The Test message is sent over the data link
that is being verified. Data links are tested in the transmit
direction as they are unidirectional, and therefore, it may be
possible for both nodes to (independently) exchange the Test
messages simultaneously.
To initiate the link verification procedure, the local node MUST
send a BeginVerify message over a control channel. To limit the
scope of Link Verification to a particular TE Link, the
LOCAL_LINK_ID MUST be non-zero. If this field is zero, the data
links can span multiple TE links and/or they may comprise a TE link
that is yet to be configured. For the case where the LOCAL_LINK_ID
field is zero, the "Verify all Links" flag of the BEGIN_VERIFY
object is used to distinguish between data links that span multiple
TE links and those that have not yet been assigned to a TE link.
Specifically, verification of data links that span multiple TE links
is indicated by setting the LOCAL_LINK_ID field to zero and setting
the "Verify all Links" flag. Verification of data links that have
not yet been assigned to a TE link is indicated by setting the
LOCAL_LINK_ID field to zero and clearing the "Verify all Links"
flag.
The BeginVerify message also contains the number of data links that
are to be verified; the interval (called VerifyInterval) at which
the Test messages will be sent; the encoding scheme and transport
mechanisms that are supported; the data rate for Test messages; and,
when the data links correspond to fibers, the wavelength identifier
over which the Test messages will be transmitted.
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If the remote node receives a BeginVerify message and it is ready to
process Test messages, it MUST send a BeginVerifyAck message back to
the local node specifying the desired transport mechanism for the
TEST messages. The remote node includes a 32-bit node unique
VerifyId in the BeginVerifyAck message. The VerifyId is then used in
all corresponding verification messages to differentiate them from
different LMP peers and/or parallel Test procedures. When the local
node receives a BeginVerifyAck message from the remote node, it may
begin testing the data links by transmitting periodic Test messages
over each data link. The Test message includes the VerifyId and the
local Interface Id for the associated data link. The remote node
MUST send either a TestStatusSuccess or a TestStatusFailure message
in response for each data link. A TestStatusAck message MUST be sent
to confirm receipt of the TestStatusSuccess and TestStatusFailure
messages.
It is also permissible for the sender to terminate the Test
procedure anytime after sending the BeginVerify message. An
EndVerify message SHOULD be sent for this purpose.
Message correlation is done using message identifiers and the Verify
Id; this enables verification of data links, belonging to different
link bundles or LMP sessions, in parallel.
When the Test message is received, the received Interface Id (used
in GMPLS as either a Port/Wavelength label or Component Interface
Identifier depending on the configuration) is recorded and mapped to
the local Interface Id for that data link, and a TestStatusSuccess
message MUST be sent. The TestStatusSuccess message includes the
local Interface Id and the remote Interface Id (received in the Test
message), along with the VerifyId received in the Test message. The
receipt of a TestStatusSuccess message indicates that the Test
message was detected at the remote node and the physical
connectivity of the data link has been verified. When the
TestStatusSuccess message is received, the local node SHOULD mark
the data link as UP and send a TestStatusAck message to the remote
node. If, however, the Test message is not detected at the remote
node within an observation period (specified by the
VerifyDeadInterval), the remote node will send a TestStatusFailure
message over the control channel indicating that the verification of
the physical connectivity of the data link has failed. When the
local node receives a TestStatusFailure message, it SHOULD mark the
data link as FAILED and send a TestStatusAck message to the remote
node. When all the data links on the list have been tested, the
local node SHOULD send an EndVerify message to indicate that testing
is complete on this link.
If the local/remote data link mappings are known, then the link
verification procedure can be optimized by testing the data links in
a defined order known to both nodes. The suggested criteria for this
ordering is in increasing value of the Remote_Interface_ID.
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Both the local and remote nodes SHOULD maintain the complete list of
Interface Id mappings for correlation purposes.
5.1. Example of Link Connectivity Verification
Figure 1 shows an example of the link verification scenario that is
executed when a link between Node A and Node B is added. In this
example, the TE link consists of three free ports (each transmitted
along a separate fiber) and is associated with a bi-directional
control channel (indicated by a "c"). The verification process is as
follows:
o A sends a BeginVerify message over the control channel to B
indicating it will begin verifying the ports that form the TE
link. The LOCAL_LINK_ID object carried in the BeginVerify
message carries the identifier (IP address or interface index)
that A assigns to the link.
o Upon receipt of the BeginVerify message, B creates a VerifyId
and binds it to the TE Link from A. This binding is used later
when B receives the Test messages from A, and these messages
carry the VerifyId. B discovers the identifier (IP address or
interface index) that A assigns to the TE link by examining the
LOCAL_LINK_ID object carried in the received BeginVerify
message. (If the data ports are not yet assigned to the TE
Link, the binding is limited to the Node Id of A.) In response
to the BeginVerify message, B sends to A the BeginVerifyAck
message. The LOCAL_LINK_ID object carried in the BeginVerifyAck
message is used to carry the identifier (IP address or
interface index) that B assigns to the TE link. The
REMOTE_LINK_ID object carried in the BeginVerifyAck message is
used to bind the TE link Ids assigned by both A and B. The
VerifyId is returned to A in the BeginVerifyAck message over
the control channel.
o When A receives the BeginVerifyAck message, it begins
transmitting periodic Test messages over the first port
(Interface Id=1). The Test message includes the Interface Id
for the port and the VerifyId that was assigned by B.
o When B receives the Test messages, it maps the received
Interface Id to its own local Interface Id = 10 and transmits a
TestStatusSuccess message over the control channel back to PXC
A. The TestStatusSuccess message includes both the local and
received Interface Ids for the port as well as the VerifyId.
The VerifyId is used to determine the local/remote TE link
identifiers (IP addresses or interface indices) for which the
data links belong.
o A will send a TestStatusAck message over the control channel
back to B indicating it received the TestStatusSuccess message.
o The process is repeated until all of the ports are verified.
o At this point, A will send an EndVerify message over the
control channel to B to indicate that testing is complete.
o B will respond by sending an EndVerifyAck message over the
control channel back to A.
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Note that this procedure can be used to "discover" the
connectivity of the data ports.
+---------------------+ +---------------------+
+ + + +
+ PXC A +<-------- c --------->+ PXC B +
+ + + +
+ + + +
+ 1 +--------------------->+ 10 +
+ + + +
+ + + +
+ 2 + /---->+ 11 +
+ + /----/ + +
+ + /---/ + +
+ 3 +----/ + 12 +
+ + + +
+ + + +
+ 4 +--------------------->+ 14 +
+ + + +
+---------------------+ +---------------------+
Figure 1: Example of link connectivity between PXC A and PXC B.
6. Fault Management
In this section, an optional LMP procedure is described that is used
to manage failures by rapid notification of the status of one or
more data channels of a TE Link. The scope of this procedure is
within a TE link, and as such, the use of this procedure is
negotiated as part of the LinkSummary exchange. The procedure can be
used to rapidly isolate link failures and is designed to work for
both unidirectional and bi-directional LSPs.
An important implication of using PXCs is that traditional methods
that are used to monitor the health of allocated data links in OEO
nodes (e.g., DXCs) may no longer be appropriate, since PXCs are
transparent to the bit-rate, format, and wavelength. Instead, fault
detection is delegated to the physical layer (i.e., loss of light or
optical monitoring of the data) instead of layer 2 or layer 3.
Recall that a TE link connecting two nodes may consist of a number
of data links. If one or more data links fail between two nodes, a
mechanism must be used for rapid failure notification so that
appropriate protection/restoration mechanisms can be initiated. If
the failure is subsequently cleared, then a mechanism must be used
to notify that the failure is clear and the channel status is OK.
6.1. Fault Detection
Fault detection should be handled at the layer closest to the
failure; for optical networks, this is the physical (optical) layer.
One measure of fault detection at the physical layer is detecting
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loss of light (LOL). Other techniques for monitoring optical signals
are still being developed and will not be further considered in this
document. However, it should be clear that the mechanism used for
fault notification in LMP is independent of the mechanism used to
detect the failure, but simply relies on the fact that a failure is
detected.
6.2. Fault Localization Procedure
If data links fail between two PXCs, the power monitoring system in
all of the downstream nodes may detect LOL and indicate a failure.
To avoid multiple alarms stemming from the same failure, LMP
provides a failure notification through the ChannelStatus message.
This message may be used to indicate that a single data channel has
failed, multiple data channels have failed, or an entire TE link has
failed. Failure correlation is done locally at each node upon
receipt of the failure notification.
To localize a fault to a particular link between adjacent OXCs, a
downstream node (downstream in terms of data flow) that detects data
link failures will send a ChannelStatus message to its upstream
neighbor indicating that a failure has occurred (bundling together
the notification of all of the failed data links). An upstream node
that receives the ChannelStatus message MUST send a ChannelStatusAck
message to the downstream node indicating it has received the
ChannelStatus message. The upstream node should correlate the
failure to see if the failure is also detected locally (including
ingress side) for the corresponding LSP(s). If, for example, the
failure is clear on the input of the upstream node or internally,
then the upstream node will have localized the failure. Once the
failure is correlated, the upstream node SHOULD send a ChannelStatus
message to the downstream node indicating that the channel is failed
or is ok. If a ChannelStatus message is not received by the
downstream node, it SHOULD send a ChannelStatusRequest message for
the channel in question. Once the failure has been localized, the
signaling protocols may be used to initiate span or path protection
and restoration procedures.
If all of the data links of a TE link have failed, then the upstream
node MAY be notified of the TE link failure without specifying each
data link of the failed TE link. This is done by sending failure
notification in a ChannelStatus message identifying the TE Link
without including the Interface Ids in the CHANNEL_STATUS object.
6.3. Examples of Fault Localization
In Fig. 2, a sample network is shown where four nodes are connected
in a linear array configuration. The control channels are bi-
directional and are labeled with a "c". All LSPs are also bi-
directional.
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In the first example [see Fig. 2(a)], there is a failure on one
direction of the bi-directional LSP. Node 4 will detect the failure
and will send a ChannelStatus message to Node 3 indicating the
failure (e.g., LOL) to the corresponding upstream node. When Node 3
receives the ChannelStatus message from Node 4, it returns a
ChannelStatusAck message back to Node 4 and correlates the failure
locally. When Node 3 correlates the failure and verifies that it is
CLEAR, it has localized the failure to the data link between Node 3
and Node 4. At that time, Node 3 should send a ChannelStatus message
to Node 4 indicating that the failure has been localized.
In the second example [see Fig. 2(b)], a single failure (e.g., fiber
cut) affects both directions of the bi-directional LSP. Node 2 (Node
3) will detect the failure of the upstream (downstream) direction
and send a ChannelStatus message to the upstream (in terms of data
flow) node indicating the failure (e.g., LOL). Simultaneously
(ignoring propagation delays), Node 1 (Node 4) will detect the
failure on the upstream (downstream) direction, and will send a
ChannelStatus message to the corresponding upstream (in terms of
data flow) node indicating the failure. Node 2 and Node 3 will have
localized the two directions of the failure.
+-------+ +-------+ +-------+ +-------+
+ Node1 + + Node2 + + Node3 + + Node4 +
+ +-- c ---+ +-- c ---+ +-- c ---+ +
----+---\ + + + + + + +
<---+---\\--+--------+-------+---\ + + + /--+--->
+ \--+--------+-------+---\\---+-------+---##---+---//--+----
+ + + + \---+-------+--------+---/ +
+ + + + + + (a) + +
----+-------+--------+---\ + + + + +
<---+-------+--------+---\\--+---##---+--\ + + +
+ + + \--+---##---+--\\ + + +
+ + + + (b) + \\--+--------+-------+--->
+ + + + + \--+--------+-------+----
+ + + + + + + +
+-------+ +-------+ +-------+ +-------+
Figure 2: Two types of data link failures are shown
(indicated by ## in the figure): (A) a data link
corresponding to the downstream direction of a bi-directional
LSP fails, (B) two data links corresponding to both
directions of a bi-directional LSP fail. The control channel
connecting two nodes is indicated with a "c".
6.4. Channel Activation Indication
The ChannelStatus message may also be used to notify an LMP neighbor
that the data link should be actively monitored. This is called
Channel Activation Indication. This is particularly useful in
networks with transparent nodes where the status of data links may
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need to be triggered using control channel messages. For example, if
a data link is pre-provisioned and the physical link fails after
verification and before inserting user traffic, a mechanism is
needed to indicate the data link should be active or the failure may
not be able to be detected.
The ChannelStatus message is used to indicate that a channel or
group of channels are now active. The ChannelStatusAck message MUST
be transmitted upon receipt of a ChannelStatus message. When a
ChannelStatus message is received, the corresponding data link(s)
MUST be put into the Active state. If upon putting them into the
Active state, a failure is detected, the ChannelStatus message
SHOULD be transmitted as described in Section 6.2.
6.5. Channel Deactivation Indication
The ChannelStatus message may also be used to notify an LMP neighbor
that the data link no longer needs to be actively monitored. This is
the counterpart to the Channel Active Indication.
When a ChannelStatus message is received with Channel Deactive
Indication, the corresponding data link(s) MUST be taken out of the
Active state.
7. Message_Id Usage
The MESSAGE_ID and MESSAGE_ID_ACK objects are included in LMP
messages to support reliable message delivery. This section
describes the usage of these objects. The MESSAGE_ID and
MESSAGE_ID_ACK objects contain a Message_Id field. Only one
MESSAGE_ID/MESSAGE_ID_ACK object may be included in any LMP message.
For control channel specific messages, the Message_Id field is
within the scope of the CCID. For TE link specific messages, the
Message_Id field is within the scope of the LMP adjacency.
The Message_Id field of the MESSAGE_ID object contains a generator
selected value. This value MUST be monotonically increasing. A value
is considered to be previously used when it has been sent in an LMP
message with the same CCID (for control channel specific messages)
or LMP adjacency (for TE Link specific messages). The Message_Id
field of the MESSAGE_ID_ACK object contains the Message_Id field of
the message being acknowledged.
Unacknowledged messages sent with the MESSAGE_ID object SHOULD be
retransmitted until the message is acknowledged or until a retry
limit is reached (see also Section 10).
Note that the 32-bit Message_Id value MAY wrap. The following
expression may be used to test if a newly received Message_Id value
is less than a previously received value:
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If ((int) old_id û (int) new_id > 0) {
New value is less than old value;
}
Nodes processing incoming messages SHOULD check to see if a newly
received message is out of order and can be ignored. Out-of-order
messages can be identified by examining the value in the Message_Id
field.
If the message is a Config message, and the Message_Id value is less
than the largest Message_Id value previously received from the
sender for the CCID, then the message SHOULD be treated as being out
of order.
If the message is a LinkSummary message and the Message_Id value is
less than the largest Message_Id value previously received from the
sender for the TE Link, then the message SHOULD be treated as being
out of order.
If the message is a ChannelStatus message and the Message_Id value
is less than the largest Message_Id value previously received from
the sender for the specified TE link, then the receiver SHOULD check
the Message_Id value previously received for the state of each data
channel included in the ChannelStatus message. If the Message_Id
value is greater than the most recently received Message_Id value
associated with at least one of the data channels included in the
message, the message MUST NOT be treated as out of order; otherwise
the message SHOULD be treated as being out of order. However, the
state of any data channel MUST NOT be updated if the Message_Id
value is less than the most recently received Message_Id value
associated with the data channel.
All other messages MUST NOT be treated as out-of-order.
8. Graceful Restart
This section describes the mechanism to resynchronize the LMP state
after a control plane restart. A control plane restart may occur
when bringing up the first control channel after an LMP adjacency
has failed, or as a result of an LMP component restart. The latter
is detected by setting the "LMP Restart" bit in the Common Header of
the LMP messages. When the control plane fails due to the loss of
the control channel (rather than an LMP component restart), the LMP
Link information should be retained. It is possible that a node may
be capable of retaining the LMP Link information across an LMP
component restart. However, in both cases the status of the data
channels MUST be synchronized.
It is assumed the Local Interface Ids remain stable across a control
plane restart.
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After the control plane of a node restarts, the control channel(s)
must be re-established using the procedures of Section 3.1.
If the control plane failure was the result of an LMP component
restart, then the "LMP Restart" flag MUST be set in LMP messages
until a Hello message is received with the RcvSeqNum equal to the
local TxSeqNum. This indicates that the control channel is UP and
the LMP neighbor has detected the restart.
The following assumes that the LMP component restart only occurred
on one end of the TE Link. If the LMP component restart occurred on
both ends of the TE Link, the normal procedures for LinkSummary
should be used, as described in Section 4.
Once a control channel is UP, the LMP neighbor MUST send a
LinkSummary message for each TE Link across the adjacency. All the
objects of the LinkSummary message MUST have the N-bit set to 0
indicating that the parameters are non-negotiable. This provides the
local/remote Link Id and Interace Id mappings, the associated
Link/Data channel parameters, and indication of which data links are
currently allocated to user traffic. When a node receives the
LinkSummary message, it checks its local configuration. If the node
is capable of retaining the LMP Link information across a restart,
it must process the LinkSummary message as described in Section 4
with the exception that the allocated/deallocated flag of the
DATA_LINK object received in the LinkSummary message MUST take
precedence over any local value. If, however, the node was not
capable of retaining the LMP Link information across a restart, the
node MUST accept the Link/Data channel parameters of the received
LinkSummary message and respond with a LinkSummaryAck message.
Upon completion of the LinkSummary exchange, the node that has
restarted the control plane SHOULD send a ChannelStatusRequest
message for that TE link. The node SHOULD also verify the
connectivity of all unallocated data channels.
9. Addressing
All LMP messages are sent directly over IP (except, in some cases,
the Test messages are limited by the transport mechanism for in-band
messaging). The destination address of the IP packet MAY be either
the address learned in the Configuration procedure (i.e., the Source
IP address found in the IP header of the received Config message),
an IP address configured on the remote node, or the node ID. The
Config message is an exception as described below.
The manner in which a Config message is addressed may depend on the
signaling transport mechanism. When the transport mechanism is a
point-to-point link, Config messages SHOULD be sent to the Multicast
address (224.0.0.1). Otherwise, Config messages MUST be sent to an
IP address on the neighboring node. This may be configured at both
ends of the control channel or may be automatically discovered.
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10. Exponential Back-off Procedures
This section is based on [RFC2961] and provides exponential backup
procedures for message retransmission. Implementations MUST use the
described procedures or their equivalent.
10.1. Operation
The following operation is one possible mechanism for exponential
back-off retransmission of unacknowledged LMP messages. The sending
node retransmits the message until an acknowledgement message is
received or until a retry limit is reached. When the sending node
receives the acknowledgement, retransmission of the message is
stopped. The interval between message retransmission is governed by
a rapid retransmission timer. The rapid retransmission timer starts
at a small interval and increases exponentially until it reaches a
threshold.
The following time parameters are useful to characterize the
procedures:
Rapid retransmission interval Ri:
Ri is the initial retransmission interval for unacknowledged
messages. After sending the message for the first time, the
sending node will schedule a retransmission after Ri
milliseconds.
Rapid retry limit Rl:
Rl is the maximum number of times a message will be transmitted
without being acknowledged.
Increment value Delta:
Delta governs the speed with which the sender increases the
retransmission interval. The ratio of two successive
retransmission intervals is (1 + Delta).
Suggested default values for an initial retransmission interval (Ri)
of 500ms, a power of 2 exponential back-off (Delta = 1) and a retry
limit of 3.
10.2. Retransmission Algorithm
After a node transmits a message requiring acknowledgement, it
should immediately schedule a retransmission after Ri seconds. If a
corresponding acknowledgement message is received before Ri seconds,
then message retransmission SHOULD be canceled. Otherwise, it will
retransmit the message after (1+Delta)*Ri seconds. The
retransmission will continue until either an appropriate
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acknowledgement message is received or the rapid retry limit, Rl,
has been reached.
A sending node can use the following algorithm when transmitting a
message that requires acknowledgement:
Prior to initial transmission, initialize Rk = Ri and Rn = 0.
while (Rn++ < Rl) {
transmit the message;
wake up after Rk milliseconds;
Rk = Rk * (1 + Delta);
}
/* acknowledged message or no reply from receiver and Rl
reached*/
do any needed clean up;
exit;
Asynchronously, when a sending node receives a corresponding
acknowledgment message, it will change the retry count, Rn, to Rl.
Note that the transmitting node does not advertise or negotiate the
use of the described exponential back-off procedures in the Config
or LinkSummary messages.
11. IANA Considerations
LMP defines the following name spaces that require management:
- Msg Type Name Space.
- LMP Object Class name space.
- LMP Object Class type (C-Type). These are unique within the Object
Class.
Following the policies outlined in [IANA], Msg Type, Object Class,
and Class type are allocated through an IETF Consensus action.
12. LMP Finite State Machines
12.1. Control Channel FSM
The control channel FSM defines the states and logics of operation
of an LMP control channel. The description of FSM state transitions
and associated actions is given in Section 3.
12.1.1. Control Channel States
A control channel can be in one of the states described below. Every
state corresponds to a certain condition of the control channel and
is usually associated with a specific type of LMP message that is
periodically transmitted to the far end.
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Down: This is the initial control channel state. In this
state, no attempt is being made to bring the control
channel up and no LMP messages are sent. The control
channel parameters should be set to the initial values.
ConfigSnd: The control channel is in the parameter negotiation
state. In this state the node periodically sends a
Config message, and is expecting the other side to
reply with either a ConfigAck or ConfigNack message.
The FSM does not transition into the Active state until
the remote side positively acknowledges the parameters.
ConfRcv: The control channel is in the parameter negotiation
state. In this state, the node is waiting for
acceptable configuration parameters from the remote
side. Once such parameters are received and
acknowledged, the FSM can transition to the Active
state.
Active: In this state the node periodically sends a Hello
message and is waiting to receive a valid Hello
message. Once a valid Hello message is received, it can
transition to the UP state.
Up: The CC is in an operational state. The node receives
valid Hello messages and sends Hello messages.
GoingDown: A CC may go into this state because of administrative
action. While a CC is in this state, the node sets the
ControlChannelDown bit in all the messages it sends.
12.1.2. Control Channel Events
Operation of the LMP control channel is described in terms of FSM
states and events. Control channel Events are generated by the
underlying protocols and software modules, as well as by the packet
processing routines and FSMs of associated TE links. Every event has
its number and a symbolic name. Description of possible control
channel events is given below.
1 : evBringUp: This is an externally triggered event indicating
that the control channel negotiation should begin.
This event, for example, may be triggered by an
operator command, by the successful completion of
a control channel bootstrap procedure, or by
configuration. Depending on the configuration,
this will trigger either
1a) the sending of a Config message,
1b) a period of waiting to receive a Config
message from the remote node.
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2 : evCCDn: This event is generated when there is indication
that the control channel is no longer available.
3 : evConfDone: This event indicates a ConfigAck message has been
received, acknowledging the Config parameters.
4 : evConfErr: This event indicates a ConfigNack message has been
received, rejecting the Config parameters.
5 : evNewConfOK: New Config message was received from neighbor and
positively Acknowledged.
6 : evNewConfErr: New Config message was received from neighbor and
rejected with a ConfigNack message.
7 : evContenWin: New Config message was received from neighbor at
the same time a Config message was sent to the
neighbor. The Local node wins the contention. As a
result, the received Config message is ignored.
8 : evContenLost: New Config message was received from neighbor at
the same time a Config message was sent to the
neighbor. The Local node loses the contention.
8a) The Config message is positively
Acknowledged.
8b) The Config message is negatively
Acknowledged.
9 : evAdminDown: The administrator has requested that the control
channel is brought down administratively. Hello
messages (with ControlChannelDown flag set) SHOULD
be sent for HelloDeadInterval seconds or until an
LMP message is received over the control channel
with the ControlChannelDown flag set.
10: evNbrGoesDn: A packet with ControlChannelDown flag is received
from the neighbor.
11: evHelloRcvd: A Hello packet with expected SeqNum has been
received.
12: evHoldTimer: The HelloDeadInterval timer has expired indicating
that no Hello packet has been received. This moves
the control channel back into the Negotiation
state, and depending on the local configuration,
this will trigger either
12a) the sending of periodic Config messages,
12b) a period of waiting to receive Config
messages from the remote node.
13: evSeqNumErr: A Hello with unexpected SeqNum received and
discarded.
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14: evReconfig: Control channel parameters have been reconfigured
and require renegotiation.
15: evConfRet: A retransmission timer has expired and a Config
message is resent.
16: evHelloRet: The HelloInterval timer has expired and a Hello
packet is sent.
17: evDownTimer: A timer has expired and no messages have been
received with the ControlChannelDown flag set.
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12.1.3. Control Channel FSM Description
Figure 3 illustrates operation of the control channel FSM
in a form of FSM state transition diagram.
+--------+
+----------------->| |<--------------+
| +--------->| Down |<----------+ |
| |+---------| |<-------+ | |
| || +--------+ | | |
| || | ^ 2,9| 2| 2|
| ||1b 1a| | | | |
| || v |2,9 | | |
| || +--------+ | | |
| || +->| |<------+| | |
| || 4,7,| |ConfSnd | || | |
| || 14,15+--| |<----+ || | |
| || +--------+ | || | |
| || 3,8a| | | || | |
| || +---------+ |8b 14,12a| || | |
| || | v | || | |
| |+-|------>+--------+ | || | |
| | | +->| |-----|-|+ | |
| | |6,14| |ConfRcv | | | | |
| | | +--| |<--+ | | | |
| | | +--------+ | | | | |
| | | 5| ^ | | | | |
| | +---------+ | | | | | | |
| | | | | | | | | |
| | v v |6,12b | | | | |
| |10 +--------+ | | | | |
| +----------| | | | | | |
| | +--| Active |---|-+ | | |
10,17| | 5,16| | |-------|---+ |
+-------+ 9 | 13 +->| | | | |
| Going |<--|----------+--------+ | | |
| Down | | 11| ^ | | |
+-------+ | | |5 | | |
^ | v | 6,12b| | |
|9 |10 +--------+ | |12a,14 |
| +----------| |---+ | |
| | Up |-------+ |
+------------------| |---------------+
+--------+
| ^
| |
+---+
11,13,16
Figure 3: Control Channel FSM
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Event evCCDn always forces the FSM to the Down State. Events
evHoldTimer evReconfig always force the FSM to the Negotiation state
(either ConfigSnd or ConfigRcv).
12.2. TE Link FSM
The TE Link FSM defines the states and logics of operation of an LMP
TE Link.
12.2.1. TE Link States
An LMP TE link can be in one of the states described below. Every
state corresponds to a certain condition of the TE link and is
usually associated with a specific type of LMP message that is
periodically transmitted to the far end via the associated control
channel or in-band via the data links.
Down: There are no data links allocated to the TE link.
Init: Data links have been allocated to the TE link, but the
configuration has not yet been synchronized with the LMP
neighbor.
Up: This is the normal operational state of the TE link. At
least one primary CC is required to be operational
between the nodes sharing the TE link.
Degraded: In this state, all primary CCs are down, but the TE link
still includes some data links that are allocated to
data traffic.
12.2.2. TE Link Events
Operation of the LMP TE link is described in terms of FSM states and
events. TE Link events are generated by the packet processing
routines and by the FSMs of the associated primary control
channel(s) and the data links. Every event has its number and a
symbolic name. Description of possible control channel events is
given below.
1 : evDCUp: One or more data channels have been enabled and
assigned to the TE Link.
2 : evSumAck: LinkSummary message received and positively
acknowledged.
3 : evSumNack: LinkSummary message received and negatively
acknowledged.
4 : evRcvAck: LinkSummaryAck message received acknowledging
the TE Link Configuration.
5 : evRcvNack: LinkSummaryNack message received.
6 : evSumRet: Retransmission timer has expired and LinkSummary
message is resent.
7 : evCCUp: First active control channel goes up.
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8 : evCCDown: Last active control channel goes down.
9 : evDCDown: Last data channel of TE Link has been removed.
12.2.3. TE Link FSM Description
Figure 4 illustrates operation of the LMP TE Link FSM in a form of
FSM state transition diagram.
3,7,8
+--+
| |
| v
+--------+
| |
+------------>| Down |<---------+
| | | |
| +--------+ |
| | ^ |
| 1| |9 |
| v | |
| +--------+ |
| | |<-+ |
| | Init | |3,5,6 |9
| | |--+ 7,8 |
9| +--------+ |
| | |
| 2,4| |
| v |
+--------+ 7 +--------+ |
| |------>| |----------+
| Deg | | Up |
| |<------| |
+--------+ 8 +--------+
| ^
| |
+--+
2,3,4,5,6
Figure 4: LMP TE Link FSM
In the above FSM, the sub-states that may be implemented when the
link verification procedure is used have been omitted.
12.3. Data Link FSM
The data link FSM defines the states and logics of operation of a
port or component link within an LMP TE link. Operation of a data
link is described in terms of FSM states and events. Data-bearing
links can either be in the active (transmitting) mode, where Test
messages are transmitted from them, or the passive (receiving) mode,
where Test messages are received through them. For clarity, separate
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FSMs are defined for the active/passive data-bearing links; however,
a single set of data link states and events are defined.
12.3.1. Data Link States
Any data link can be in one of the states described below. Every
state corresponds to a certain condition of the TE link.
Down: The data link has not been put in the resource pool
(i.e., the link is not æin serviceÆ
Test: The data link is being tested. An LMP Test message is
periodically sent through the link.
PasvTest: The data link is being checked for incoming test
messages.
Up/Free: The link has been successfully tested and is now put
in the pool of resources (in-service). The link has
not yet been allocated to data traffic.
Up/Allocated: The link is UP and has been allocated for data
traffic.
12.3.2. Data Link Events
Data bearing link events are generated by the packet processing
routines and by the FSMs of the associated control channel and the
TE link. Every event has its number and a symbolic name. Description
of possible data link events is given below:
1 :evCCUp: CC has gone up.
2 :evCCDown: LMP neighbor connectivity is lost. This indicates
the last LMP control channel has failed between
neighboring nodes.
3 :evStartTst: This is an external event that triggers the sending
of Test messages over the data bearing link.
4 :evStartPsv: This is an external event that triggers the
listening for Test messages over the data bearing
link.
5 :evTestOK: Link verification was successful and the link can
be used for path establishment.
(a) This event indicates the Link Verification
procedure (see Section 5) was successful
for this data link and a TestStatusSuccess
message was received over the control
channel.
(b) This event indicates the link is ready for
path establishment, but the Link
Verification procedure was not used. For
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in-band signaling of the control channel,
the control channel establishment may be
sufficient to verify the link.
6 :evTestRcv: Test message was received over the data port and a
TestStatusSuccess message is transmitted over the
control channel.
7 :evTestFail: Link verification returned negative results. This
could be because (a) a TestStatusFailure message
was received, or (b) the Verification procedure has
ended without receiving a TestStatusSuccess or
TestStatusFailure message for the data link.
8 :evPsvTestFail:Link verification returned negative results. This
indicates that a Test message was not detected and
either (a) the VerifyDeadInterval has expired or
(b) the Verification procedure has ended and the
VerifyDeadInterval has not yet expired.
9 :evLnkAlloc: The data link has been allocated.
10:evLnkDealloc: The data link has been deallocated.
11:evTestRet: A retransmission timer has expired and the Test
message is resent.
12:evSummaryFail:The LinkSummary did not match for this data port.
13:evLocalizeFail:A Failure has been localized to this data link.
14:evdcDown: The data channel is no longer available.
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12.3.3. Active Data Link FSM Description
Figure 5 illustrates operation of the LMP active data link FSM in a
form of FSM state transition diagram.
+------+
| |<-------+
+--------->| Down | |
| +----| |<-----+ |
| | +------+ | |
| |5b 3| ^ | |
| | | |7 | |
| | v | | |
| | +------+ | |
| | | |<-+ | |
| | | Test | |11 | |
| | | |--+ | |
| | +------+ | |
| | 5a| 3^ | |
| | | | | |
| | v | | |
|12 | +---------+ | |
| +-->| |14 | |
| | Up/Free |----+ |
+---------| | |
+---------+ |
9| ^ |
| | |
v |10 |
+---------+ |
| |13 |
|Up/Alloc |------+
| |
+---------+
Figure 5: Active LMP Data Link FSM
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12.3.4. Passive Data Link FSM Description
Figure 6 illustrates operation of the LMP passive data link FSM in a
form of FSM state transition diagram.
+------+
| |<------+
+---------->| Down | |
| +-----| |<----+ |
| | +------+ | |
| |5b 4| ^ | |
| | | |8 | |
| | v | | |
| | +----------+ | |
| | | PasvTest | | |
| | +----------+ | |
| | 6| 4^ | |
| | | | | |
| | v | | |
|12 | +---------+ | |
| +--->| Up/Free |14 | |
| | |---+ |
+----------| | |
+---------+ |
9| ^ |
| | |
v |10 |
+---------+ |
| |13 |
|Up/Alloc |-----+
| |
+---------+
Figure 6: Passive LMP Data Link FSM
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13. LMP Message Formats
All LMP messages are IP encoded (except, in some cases, the Test
messages are limited by the transport mechanism for in-band
messaging) and run over UDP with port number xxx - TBA (to be
assigned) by IANA.
13.1. Common Header
In addition to the standard IP header, all LMP messages (except, in
some cases, the Test messages which are limited by the transport
mechanism for in-band messaging) have the following common header:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vers | (Reserved) | Flags | Msg Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LMP Length | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Vers: 4 bits
Protocol version number. This is version 1.
Flags: 8 bits. The following values are defined. All other values
are reserved.
0x01: ControlChannelDown
0x02: LMP Restart
This bit is set to indicate the LMP component has
restarted. This flag may be reset to 0 when a Hello
message is received with RcvSeqNum equal to the local
TxSeqNum.
Msg Type: 8 bits. The following values are defined. All other values
are reserved.
1 = Config
2 = ConfigAck
3 = ConfigNack
4 = Hello
5 = BeginVerify
6 = BeginVerifyAck
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7 = BeginVerifyNack
8 = EndVerify
9 = EndVerifyAck
10 = Test
11 = TestStatusSuccess
12 = TestStatusFailure
13 = TestStatusAck
14 = LinkSummary
15 = LinkSummaryAck
16 = LinkSummaryNack
17 = ChannelStatus
18 = ChannelStatusAck
19 = ChannelStatusRequest
20 = ChannelStatusResponse
All of the messages are sent over the control channel EXCEPT
the Test message, which is sent over the data link that is
being tested.
LMP Length: 16 bits
The total length of this LMP message in bytes, including the
common header and any variable-length objects that follow.
Checksum: 16 bits
The standard IP checksum of the entire contents of the LMP
message, starting with the LMP message header. This checksum is
calculated as the 16-bit one's complement of the one's
complement sum of all the 16-bit words in the packet. If the
packet's length is not an integral number of 16-bit words, the
packet is padded with a byte of zero before calculating the
checksum.
13.2. LMP Object Format
LMP messages are built using objects. Each object is identified by
its Object Class and Class-type. Each object has a name, which is
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always capitalized in this document. LMP objects can be either
negotiable or non-negotiable (identified by the N bit in the object
header). Negotiable objects can be used to let the devices agree on
certain values. Non-negotiable objects are used for announcement of
specific values that do not need or do not allow negotiation.
The format of the LMP object is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|N| C-Type | Class | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// (object contents) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
N: 1 bit
The N flag indicates if the object is negotiable (N=1) or non-
negotiable (N=0).
C-Type: 7 bits
Class-type, unique within an Object Class. Values are defined
in Section 14.
Class: 8 bits
The Class indicates the object type. Each object has a name,
which is always capitalized in this document.
Length: 16 bits
The Length field indicates the length of the object in bytes,
including the N, C-Type, Class, and Length fields.
13.3. Parameter Negotiation Messages
13.3.1. Config Message (Msg Type = 1)
The Config message is used in the control channel negotiation phase
of LMP. The contents of the Config message are built using LMP
objects. The format of the Config message is as follows:
<Config Message> ::= <Common Header> <LOCAL_CCID> <MESSAGE_ID>
<LOCAL_NODE_ID> <CONFIG>
The above transmission order SHOULD be followed.
The MESSAGE_ID is within the scope of the CCID.
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The Config message MUST be periodically transmitted until (1) it
receives a ConfigAck or ConfigNack message, (2) a timeout expires
and no ConfigAck or ConfigNack message has been received, or (3) it
receives a Config message from the remote node and has lost the
contention (e.g., the Node Id of the remote node is higher than the
Node Id of the local node). Both the retransmission interval and the
timeout period are local configuration parameters.
13.3.2. ConfigAck Message (Msg Type = 2)
The ConfigAck message is used to acknowledge receipt of the Config
message and indicate agreement on all parameters.
<ConfigAck Message> ::= <Common Header> <LOCAL_CCID> <LOCAL_NODE_ID>
<REMOTE_CCID> <MESSAGE_ID_ACK>
<REMOTE_NODE_ID>
The above transmission order SHOULD be followed.
The contents of the REMOTE_CCID, MESSAGE_ID_ACK, and REMOTE_NODE_ID
objects MUST be obtained from the Config message being acknowledged.
13.3.3. ConfigNack Message (Msg Type = 3)
The ConfigNack message is used to acknowledge receipt of the Config
message and indicate disagreement on non-negotiable parameters or
propose other values for negotiable parameters. Parameters where
agreement was reached MUST NOT be included in the ConfigNack
Message. The format of the ConfigNack message is as follows:
<ConfigNack Message> ::= <Common Header> <LOCAL_CCID>
<LOCAL_NODE_ID> <REMOTE_CCID>
<MESSAGE_ID_ACK> <REMOTE_NODE_ID> <CONFIG>
The above transmission order SHOULD be followed.
The contents of the REMOTE_CCID, MESSAGE_ID_ACK, and REMOTE_NODE_ID
objects MUST be obtained from the Config message being negatively
acknowledged.
It is possible that multiple parameters may be invalid in the Config
message.
If a negotiable CONFIG object is included in the ConfigNack message,
it MUST include acceptable values for the parameters.
If the ConfigNack message includes CONFIG objects for non-negotiable
parameters, they MUST be copied from the CONFIG objects received in
the Config message.
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If the ConfigNack message is received and only includes CONFIG
objects that are negotiable, then a new Config message SHOULD be
sent. The values in the CONFIG object of the new Config message
SHOULD take into account the acceptable values included in the
ConfigNack message.
13.4. Hello Message (Msg Type = 4)
The format of the Hello message is as follows:
<Hello Message> ::= <Common Header> <LOCAL_CCID> <HELLO>
The above transmission order SHOULD be followed.
The Hello message MUST be periodically transmitted at least once
every HelloInterval msec. If no Hello message is received within the
HelloDeadInterval, the control channel is assumed to have failed.
13.5. Link Verification
13.5.1. BeginVerify Message (Msg Type = 5)
The BeginVerify message is sent over the control channel and is used
to initiate the link verification process. The format is as follows:
<BeginVerify Message> ::= <Common Header> <LOCAL_LINK_ID>
<MESSAGE_ID> [<REMOTE_LINK_ID>]
<BEGIN_VERIFY>
The above transmission order SHOULD be followed.
To limit the scope of Link Verification to a particular TE Link, the
LOCAL_LINK_ID MUST be non-zero. If this field is zero, the data
links can span multiple TE links and/or they may comprise a TE link
that is yet to be configured. In the special case where the
LOCAL_LINK_ID field is zero, the "Verify all Links" flag of the
BEGIN_VERIFY object is used to distinguish between data links that
span multiple TE links and those that have not yet been assigned to
a TE link.
The REMOTE_LINK_ID may be included if the local/remote Link Id
mapping is known.
The REMOTE_LINK_ID MUST be non-zero if included.
The BeginVerify message MUST be periodically transmitted until (1)
the node receives either a BeginVerifyAck or BeginVerifyNack message
to accept or reject the verify process or (2) a timeout expires and
no BeginVerifyAck or BeginVerifyNack message has been received. Both
the retransmission interval and the timeout period are local
configuration parameters.
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13.5.2. BeginVerifyAck Message (Msg Type = 6)
When a BeginVerify message is received and Test messages are ready
to be processed, a BeginVerifyAck message MUST be transmitted.
<BeginVerifyAck Message> ::= <Common Header> [<LOCAL_LINK_ID>]
<MESSAGE_ID_ACK> <BEGIN_VERIFY_ACK>
<VERIFY_ID>
The above transmission order SHOULD be followed.
The LOCAL_LINK_ID may be included if the local/remote Link Id
mapping is known or learned through the BeginVerify message.
The LOCAL_LINK_ID MUST be non-zero if included.
The contents of the MESSAGE_ID_ACK object MUST be obtained from the
BeginVerify message being acknowledged.
The VERIFY_ID object contains a node-unique value that is assigned
by the generator of the BeginVerifyAck message. This value is used
to uniquely identify the Verification process from multiple LMP
neighbors and/or parallel Test procedures between the same LMP
neighbors.
13.5.3. BeginVerifyNack Message (Msg Type = 7)
If a BeginVerify message is received and a node is unwilling or
unable to begin the Verification procedure, a BeginVerifyNack
message MUST be transmitted.
<BeginVerifyNack Message> ::= <Common Header> [<LOCAL_LINK_ID>]
<MESSAGE_ID_ACK> <ERROR_CODE>
The above transmission order SHOULD be followed.
The contents of the MESSAGE_ID_ACK object MUST be obtained from the
BeginVerify message being negatively acknowledged.
If the Verification process is not supported, the ERROR_CODE MUST
indicate "Link Verification Procedure not supported".
If Verification is supported, but the node unable to begin the
procedure, the ERROR_CODE MUST indicate "Unwilling to verify". If a
BeginVerifyNack message is received with such an ERROR_CODE, the
node that originated the BeginVerify SHOULD schedule a BeginVerify
retransmission after Rf seconds, where Rf is a locally defined
parameter.
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If the Verification Transport mechanism is not supported, the
ERROR_CODE MUST indicate "Unsupported verification transport
mechanism".
If remote configuration of the TE Link Id is not supported and the
REMOTE_LINK_ID object (included in the BeginVerify message) does not
match any configured values, the ERROR_CODE MUST indicate "TE Link
Id configuration error".
The BeginVerifyNack uses BEGIN_VERIFY_ERROR_ C-Type 1.
13.5.4. EndVerify Message (Msg Type = 8)
The EndVerify message is sent over the control channel and is used
to terminate the link verification process. The EndVerify message
may be sent at any time the initiating node desires to end the
Verify procedure. The format is as follows:
<EndVerify Message> ::= <Common Header> <MESSAGE_ID> <VERIFY_ID>
The above transmission order SHOULD be followed.
The EndVerify message will be periodically transmitted until (1) an
EndVerifyAck message has been received or (2) a timeout expires and
no EndVerifyAck message has been received. Both the retransmission
interval and the timeout period are local configuration parameters.
13.5.5. EndVerifyAck Message (Msg Type =9)
The EndVerifyAck message is sent over the control channel and is
used to acknowledge the termination of the link verification
process. The format is as follows:
<EndVerifyAck Message> ::= <Common Header> <MESSAGE_ID_ACK>
<VERIFY_ID>
The above transmission order SHOULD be followed.
The contents of the MESSAGE_ID_ACK object MUST be obtained from the
EndVerify message being acknowledged.
13.5.6. Test Message (Msg Type = 10)
The Test message is transmitted over the data link and is used to
verify its physical connectivity. Unless explicitly stated in the
Verify Transport Mechanism description for the BEGIN_VERIFY class,
this is transmitted as an IP packet with payload format as follows:
<Test Message> ::= <Common Header> <LOCAL_INTERFACE_ID> <VERIFY_ID>
The above transmission order SHOULD be followed.
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Note that this message is sent over a data link and NOT over the
control channel. The transport mechanism for the Test message is
negotiated using Verify Transport Mechanism field of the
BEGIN_VERIFY object and the Verify Transport Response field of the
BEGIN_VERIFY_ACK object (see Sections 14.8 and 14.9).
The local (transmitting) node sends a given Test message
periodically (at least once every VerifyInterval ms) on the
corresponding data link until (1) it receives a correlating
TestStatusSuccess or TestStatusFailure message on the control
channel from the remote (receiving) node or (2) all active control
channels between the two nodes have failed. The remote node will
send a given TestStatus message periodically over the control
channel until it receives either a correlating TestStatusAck message
or an EndVerify message is received over the control channel.
13.5.7. TestStatusSuccess Message (Msg Type = 11)
The TestStatusSuccess message is transmitted over the control
channel and is used to transmit the mapping between the local
Interface Id and the Interface Id that was received in the Test
message.
<TestStatusSuccess Message> ::= <Common Header> <LOCAL_LINK_ID>
<MESSAGE_ID> <LOCAL_INTERFACE_ID>
<REMOTE_INTERFACE_ID> <VERIFY_ID>
The above transmission order SHOULD be followed.
The contents of the REMOTE_INTERFACE_ID object MUST be obtained from
the corresponding Test message being positively acknowledged.
13.5.8. TestStatusFailure Message (Msg Type = 12)
The TestStatusFailure message is transmitted over the control
channel and is used to indicate that the Test message was not
received.
<TestStatusFailure Message> ::= <Common Header> <MESSAGE_ID>
<VERIFY_ID>
The above transmission order SHOULD be followed.
13.5.9. TestStatusAck Message (Msg Type = 13)
The TestStatusAck message is used to acknowledge receipt of the
TestStatusSuccess or TestStatusFailure messages.
<TestStatusAck Message> ::= <Common Header> <MESSAGE_ID_ACK>
<VERIFY_ID>
The above transmission order SHOULD be followed.
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The contents of the MESSAGE_ID_ACK object MUST be obtained from the
TestStatusSuccess or TestStatusFailure message being acknowledged.
13.6. Link Summary Messages
13.6.1. LinkSummary Message (Msg Type = 14)
The LinkSummary message is used to synchronize the Interface Ids and
correlate the properties of the TE link. The format of the
LinkSummary message is as follows:
<LinkSummary Message> ::= <Common Header> <MESSAGE_ID> <TE_LINK>
<DATA_LINK> [<DATA_LINK>...]
The above transmission order SHOULD be followed.
The LinkSummary message can be exchanged at any time a link is not
in the Verification process. The LinkSummary message MUST be
periodically transmitted until (1) the node receives a
LinkSummaryAck or LinkSummaryNack message or (2) a timeout expires
and no LinkSummaryAck or LinkSummaryNack message has been received.
Both the retransmission interval and the timeout period are local
configuration parameters.
13.6.2. LinkSummaryAck Message (Msg Type = 15)
The LinkSummaryAck message is used to indicate agreement on the
Interface Id synchronization and acceptance/agreement on all the
link parameters. It is on the reception of this message that the
local node makes the TE Link Id associations.
<LinkSummaryAck Message> ::= <Common Header> <MESSAGE_ID_ACK>
The above transmission order SHOULD be followed.
13.6.3. LinkSummaryNack Message (Msg Type = 16)
The LinkSummaryNack message is used to indicate disagreement on non-
negotiated parameters or propose other values for negotiable
parameters. Parameters where agreement was reached MUST NOT be
included in the LinkSummaryNack message.
<LinkSummaryNack Message> ::= <Common Header> <MESSAGE_ID_ACK>
<ERROR_CODE> [<DATA_LINK>...]
The above transmission order SHOULD be followed.
The DATA_LINK objects MUST include acceptable values for all
negotiable parameters. If the LinkSummaryNack includes DATA_LINK
objects for non-negotiable parameters, they MUST be copied from the
DATA_LINK objects received in the LinkSummary message.
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If the LinkSummaryNack message is received and only includes
negotiable parameters, then a new LinkSummary message SHOULD be
sent. The values received in the new LinkSummary message SHOULD take
into account the acceptable parameters included in the
LinkSummaryNack message.
The LinkSummaryNack message uses LINK_SUMMARY_ERROR C-Type 2.
13.7. Fault Management Messages
13.7.1. ChannelStatus Message (Msg Type = 17)
The ChannelStatus message is sent over the control channel and is
used to notify an LMP neighbor of the status of a data link. A node
that receives a ChannelStatus message MUST respond with a
ChannelStatusAck message. The format is as follows:
<ChannelStatus Message> ::= <Common Header> <LOCAL_LINK_ID>
<MESSAGE_ID> <CHANNEL_STATUS>
The above transmission order SHOULD be followed.
If the CHANNEL_STATUS object does not include any Interface Ids,
then this indicates the entire TE Link has failed.
13.7.2. ChannelStatusAck Message (Msg Type = 18)
The ChannelStatusAck message is used to acknowledge receipt of the
ChannelStatus Message. The format is as follows:
<ChannelStatusAck Message> ::= <Common Header> <MESSAGE_ID_ACK>
The above transmission order SHOULD be followed.
The contents of the MESSAGE_ID_ACK object MUST be obtained from the
ChannelStatus message being acknowledged.
13.7.3. ChannelStatusRequest Message (Msg Type = 19)
The ChannelStatusRequest message is sent over the control channel
and is used to request the status of one or more data link(s). A
node that receives a ChannelStatusRequest message MUST respond with
a ChannelStatusResponse message. The format is as follows:
<ChannelStatusRequest Message> ::= <Common Header> <LOCAL_LINK_ID>
<MESSAGE_ID>
[<CHANNEL_STATUS_REQUEST>]
The above transmission order SHOULD be followed.
Lang et al [Page 44]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
If the CHANNEL_STATUS_REQUEST object is not included, then the
ChannelStatusRequest is being used to request the status of ALL of
the data link(s) of the TE Link.
13.7.4. ChannelStatusResponse Message (Msg Type = 20)
The ChannelStatusResponse message is used to acknowledge receipt of
the ChannelStatusRequest Message and notify the LMP neighbor of the
status of the data channel(s). The format is as follows:
<ChannelStatusResponse Message> ::= <Common Header> <MESSAGE_ID_ACK>
<CHANNEL_STATUS>
The above transmission order SHOULD be followed.
The contents of the MESSAGE_ID_ACK objects MUST be obtained from the
ChannelStatusRequest message being acknowledged.
14. LMP Object Definitions
14.1. CCID (Control Channel ID) Class
Class = 1.
o C-Type = 1, LOCAL_CCID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CC_Id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
CC_Id: 32 bits
This MUST be node-wide unique and non-zero. The CC_Id
identifies the control channel of the sender associated with
the message.
This object is non-negotiable.
o C-Type = 2, REMOTE_CCID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CC_Id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
CC_Id: 32 bits
This identifies the remote nodeÆs CC_Id and MUST be non-zero.
Lang et al [Page 45]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
This object is non-negotiable.
14.2. NODE_ID Classes
Class = 2.
o C-Type = 1, LOCAL_NODE_ID Class
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Node_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Node_Id:
This identities the node that originated the LMP packet.
This object is non-negotiable.
o C-Type = 2, REMOTE_NODE_ID Class
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Node_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Node_Id:
This identities the remote node.
This object is non-negotiable.
14.3. LINK _ID Class
Class = 3
o C-Type = 1, IPv4 LOCAL_LINK_ID
o C-Type = 2, IPv4 REMOTE_LINK_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 3, IPv6 LOCAL_LINK_ID
o C-Type = 4, IPv6 REMOTE_LINK_ID
Lang et al [Page 46]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Link_Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 5, Unnumbered LOCAL_LINK_ID
o C-Type = 6, Unnumbered REMOTE_LINK_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 7, Reserved for OIF
o C-Type = 8, Reserved for OIF
Link_Id:
For LOCAL_LINK_ID, this identifies the senderÆs Link associated
with the message.
For REMOTE_LINK_ID, this identifies the remote nodeÆs Link Id
and MUST be non-zero.
This object is non-negotiable.
14.4. INTERFACE_ID Class
Class = 4
o C-Type = 1, IPv4 LOCAL_INTERFACE_ID
o C-Type = 2, IPv4 REMOTE_INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 3, IPv6 LOCAL_INTERFACE_ID
Lang et al [Page 47]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
o C-Type = 4, IPv6 REMOTE_INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Interface_Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 5, Unnumbered LOCAL_INTERFACE_ID
o C-Type = 6, Unnumbered REMOTE_INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Interface_Id:
For the LOCAL_INTERFACE_ID, this identifies the data link
(either port or component link). This value MUST be node-wide
unique and non-zero.
For the REMOTE_INTERFACE_ID, this identifies the remote nodeÆs
data link (either port or component link). The Interface Id
MUST be non-zero.
This object is non-negotiable.
14.5. MESSAGE_ID Class
Class = 5.
o C-Type=1, MessageId
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message_Id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Message_Id:
Lang et al [Page 48]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
The Message_Id field is used to identify a message. This value
is incremented and only decreases when the value wraps. This is
used for message acknowledgment.
This object is non-negotiable.
o C-Type = 2, MessageIdAck
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message_Id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Message_Id:
The Message_Id field is used to identify the message being
acknowledged. This value is copied from the MESSAGE_ID object
of the message being acknowledged.
This object is non-negotiable.
14.6. CONFIG Class
Class = 6.
o C-Type = 1, HelloConfig
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| HelloInterval | HelloDeadInterval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
HelloInterval: 16 bits.
Indicates how frequently the Hello packets will be sent and is
measured in milliseconds (ms).
HelloDeadInterval: 16 bits.
If no Hello packets are received within the HelloDeadInterval,
the control channel is assumed to have failed. The
HelloDeadInterval is measured in milliseconds (ms). The
HelloDeadInterval MUST be greater than the HelloInterval, and
SHOULD be at least 3 times the value of HelloInterval.
If the fast keep-alive mechanism of LMP is not used, the
HelloInterval and HelloDeadInterval MUST be set to zero.
14.7. HELLO Class
Lang et al [Page 49]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
Class = 7
o C-Type = 1, Hello
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TxSeqNum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RcvSeqNum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
TxSeqNum: 32 bits
This is the current sequence number for this Hello message.
This sequence number will be incremented when the sequence
number is reflected in the RcvSeqNum of a Hello packet that is
received over the control channel.
TxSeqNum=0 is not allowed.
TxSeqNum=1 is reserved to indicate that the control channel has
booted or restarted.
RcvSeqNum: 32 bits
This is the sequence number of the last Hello message received
over the control channel. RcvSeqNum=0 is reserved to indicate
that a Hello message has not yet been received.
This object is non-negotiable.
14.8. BEGIN_VERIFY Class
Class = 8.
o C-Type = 1
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | VerifyInterval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Data Links |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| EncType | (Reserved) | Verify Transport Mechanism |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TransmissionRate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Wavelength |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Lang et al [Page 50]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
Flags: 16 bits
The following flags are defined:
0x01 Verify all Links
If this bit is set, the verification process checks all
unallocated links; else it only verifies new ports or
component links that are to be added to this TE link.
0x02 Data Link Type
If set, the data links to be verified are ports,
otherwise they are component links
VerifyInterval: 16 bits
This is the interval between successive Test messages and is
measured in milliseconds (ms).
Number of Data Links: 32 bits
This is the number of data links that will be verified.
EncType: 8 bits
This is the encoding type of the data link. The defined EncType
values are consistent with the Link Encoding Type values of
[GMPLS-SIG]
Verify Transport Mechanism: 16 bits
This defines the transport mechanism for the Test Messages. The
scope of this bit mask is restricted to each link encoding
type. The local node will set the bits corresponding to the
various mechanisms it can support for transmitting LMP test
messages. The receiver chooses the appropriate mechanism in the
BeginVerifyAck message.
For SONET/SDH Encoding Type, the following flags are defined:
0x01 J0-16: 16 byte J0 Test Message
Capable of transmitting Test messages using J0 overhead
bytes with string length of 16 bytes (with CRC-7). See
table 4 of ITU G.707 [G707] for the 16-byte J0
definition. The definition of CRC-7 is found in Annex B
of ITU G.707.
Note that Due to the byte limitation, the Test message
is NOT sent as an IP packet and as such, no L2
encapsulation is used. A special Test message format is
defined as follows:
Lang et al [Page 51]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
The Test message is a 15-byte message, where the 7 most
significant bits (MSb) of each byte are usable. Due to
the byte limitation, the LMP Header is not included.
The first usable 32 bits MUST be the VerifyId that was
received in the VERIFY_ID object of the BeginVerifyAck
message. The second usable 32 bits MUST be the
Interface_Id. The next usable 8 bits are used to
determine the address type of the Interface_Id. For
IPv4, this value is 1. For unnumbered, this value is 3.
The remaining bits are Reserved.
Note that this Test Message format is only valid when
the Interface_Id is either IPv4 or unnumbered.
0x02 J0-64: 64 byte J0 Test Message
Capable of transmitting Test messages using J0
overhead bytes with string length of 64 bytes (see GR-
253-CORE [GR253]). Note that this is only appropriate
for SONET encoding and not SDH encoding.
The Test message is sent as an IP packet as defined
above.
0x04 DCCS: Test Message over the Section DCC
Capable of transmitting Test messages using the DCC
Section Overhead bytes with bit-oriented HDLC framing
format.
The Test message is sent as an IP packet as defined
above.
0x08 DCCL: Test Message over the Line DCC
Capable of transmitting Test messages using the DCC
Line Overhead bytes with bit-oriented HDLC framing
format.
The Test message is sent as an IP packet as defined
above.
0x10 Payload: Test Message transmitted in the payload
Capable of transmitting Test messages in the payload
using Packet over SONET framing using the encoding type
specified in the EncType field.
The Test message is sent as an IP packet as defined
above.
Lang et al [Page 52]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
0x20 GigE:
Capable of transmitting Test messages in the payload
TransmissionRate: 32 bits
This is the transmission rate of the data link over which the
Test messages will be transmitted. This is expressed in bytes
per second and represented in IEEE floating point format.
Wavelength: 32 bits
When a data link is assigned to a port or component link that
is capable of transmitting multiple wavelengths (e.g., a fiber
or waveband-capable port), it is essential to know which
wavelength the test messages will be transmitted over. This
value corresponds to the wavelength at which the Test messages
will be transmitted over and has local significance. If there
is no ambiguity as to the wavelength over which the message
will be sent, then this value SHOULD be set to 0.
14.9. BEGIN_VERIFY_ACK Class
Class = 9.
o C-Type = 1
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| VerifyDeadInterval | Verify_Transport_Response |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
VerifyDeadInterval: 16 bits
If a Test message is not detected within the
VerifyDeadInterval, then a node will send the TestStatusFailure
message for that data link.
Verify_Transport_Response: 16 bits
The recipient of the BeginVerify message (and the future
recipient of the TEST messages) chooses the transport mechanism
from the various types that are offered by the transmitter of
the Test messages. One and only one bit MUST be set in the
verification transport response.
This object is non-negotiable.
14.10. VERIFY_ID Class
Class = 10.
Lang et al [Page 53]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
o C-Type = 1
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| VerifyId |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
VerifyId: 32 bits
This is used to differentiate Test messages from different TE
links and/or LMP peers. This is a node-unique value that is
assigned by the recipient of the BeginVerify message.
This object is non-negotiable.
14.11. TE_LINK Class
Class = 11.
o C-Type = 1, IPv4 TE_LINK
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local_Link_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote_Link_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 2, IPv6 TE_LINK
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Local_Link_Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Remote_Link_Id (16 bytes) +
Lang et al [Page 54]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 3, Unnumbered TE_LINK
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local_Link_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote_Link_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 4, Reserved for OIF
Flags: 8 bits
The following flags are defined. All other values are reserved.
0x01 Fault Management Supported.
0x02 Link Verification Supported.
Local_Link_Id:
This identifies the nodeÆs local Link Id and MUST be non-zero.
Remote_Link_Id:
This identifies the remote nodeÆs Link Id and MUST be non-zero.
14.12. DATA_LINK Class
Class = 12.
o C-Type = 1, IPv4 DATA_LINK
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local_Interface_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote_Interface_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// (Subobjects) //
| |
Lang et al [Page 55]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 2, IPv6 DATA_LINK
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Local_Interface_Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Remote_Interface_Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// (Subobjects) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 3, Unnumbered DATA_LINK
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local_Interface_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote_Interface_Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// (Subobjects) //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Flags: 8 bits
The following flags are defined. All other values are reserved.
0x01 Interface Type: If set, the data link is a port,
otherwise it is a component link.
Lang et al [Page 56]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
0x02 Allocated Link: If set, the data link is currently
allocated for user traffic. If a single
Interface_Id is used for both the
transmit and receive data links, then
this bit only applies to the transmit
interface.
0x04 Failed Link: If set, the data link is failed and not
suitable for user traffic.
Local_Interface_Id:
This is the local identifier of the data link. This MUST be
node-wide unique and non-zero.
Remote_Interface_Id:
This is the remote identifier of the data link. This MUST be
non-zero.
Subobjects
The contents of the DATA_LINK object consist of a series of
variable-length data items called subobjects. The subobjects
are defined in section 14.12.1 below.
A DATA_LINK object may contain more than one subobject. More than
one subobject of the same Type may appear if multiple capabilities
are supported over the data link.
14.12.1. Data Link Subobjects
The contents of the DATA_LINK object include a series of variable-
length data items called subobjects. Each subobject has the form:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+---------------//------------ -+
| Type | Length | (Subobject contents) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--------------//---------------+
Type: 8 bits
The Type indicates the type of contents of the subobject.
Currently defined values are:
Type = 1, Interface Switching Capability
Length: 8 bits
The Length contains the total length of the subobject in bytes,
including the Type and Length fields. The Length MUST be at
least 4, and MUST be a multiple of 4.
Lang et al [Page 57]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
14.12.1.1. Subobject Type 1: Interface Switching Capability
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Switching Cap | EncType |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum Reservable Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum Reservable Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Switching Capability: 8 bits
This is used to identify the local Interface Switching
Capability of the TE link as defined in [GMPLS-SIG].
EncType: 8 bits
This is the encoding type of the data link. The defined EncType
values are consistent with the Link Encoding Type values of
[GMPLS-SIG].
Minimum Reservable Bandwidth: 32 bits
This is measured in bytes per second and represented in IEEE
floating point format.
Maximum Reservable Bandwidth: 32 bits
This is measured in bytes per second and represented in IEEE
floating point format.
If the interface only supports a fixed rate, the minimum and maximum
bandwidth fields are set to the same value.
14.12.1.2. Subobject Type 2: Wavelength
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Wavelength |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Wavelength: 32 bits
This value indicates the wavelength carried over the port.
Values used in this field only have significance between two
neighbors.
Lang et al [Page 58]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
14.13. CHANNEL_STATUS Class
Class = 13
o C-Type = 1, IPv4 INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Channel Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| : |
// : //
| : |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Channel Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o C-Type = 2, IPv6 INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Interface Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Channel Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| : |
// : //
| : |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Interface Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Channel Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Lang et al [Page 59]
Internet Draft draft-ietf-ccamp-lmp-04.txt June 2002
o C-Type = 3, Unnumbered INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A| Channel Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| : |
// : //
| : |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|D| Channel Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Active bit: 1 bit
This indicates that the Channel is allocated to user traffic and the
data link should be actively monitored.
Direction bit: 1 bit
This indicates the direction (transmit/receive) of the data channel
referred to in the CHANNEL_STATUS object. If set, this indicates the
data channel is in the transmit direction.
Channel_Status: 30 bits
This indicates the status condition of a data channel. The
following values are defined. All other values are reserved.
1 Signal Okay (OK): Channel is operational
2 Signal Degrade (SD): A soft failure caused by a BER
exceeding a preselected threshold. The specific BER
used to define the threshold is configured.
3 Signal Fail (SF): A hard signal failure including (but not
limited to) loss of signal (LOS), loss of frame
(LOF), or Line AIS.
This object contains one or more Interface Ids followed by a
Channel_Status field.
To indicate the status of the entire TE Link, there MUST only be one
Interface Id and it MUST be zero.
This object is non-negotiable.
14.14. CHANNEL_STATUS_REQUEST Class
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Class = 14
o C-Type = 1, IPv4 INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| : |
// : //
| : |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This object contains one or more Interface Ids.
The Length of this object is 4 + 4N in bytes, where N is the number
of Interface Ids.
o C-Type = 2, IPv4 INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Interface Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| : |
// : //
| : |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Interface Id (16 bytes) +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This object contains one or more Interface Ids.
The Length of this object is 4 + 16N in bytes, where N is the number
of Interface Ids.
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o C-Type = 3, Unnumbered INTERFACE_ID
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| : |
// : //
| : |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Id (4 bytes) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This object contains one or more Interface Ids.
The Length of this object is 4 + 4N in bytes, where N is the number
of Interface Ids.
This object is non-negotiable.
14.15. ERROR_CODE Class
Class = 20.
o C-Type = 1, BEGIN_VERIFY_ERROR
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ERROR CODE |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The following bit-values are defined:
0x01 = Link Verification Procedure not supported for this TE
Link.
0x02 = Unwilling to verify at this time
0x04 = Unsupported verification transport mechanism
0x08 = TE Link Id configuration error
All other values are Reserved.
Multiple bits may be set to indicate multiple errors.
This object is non-negotiable.
If a BeginVerifyNack message is received with Error Code 2, the node
that originated the BeginVerify SHOULD schedule a BeginVerify
retransmission after Rf seconds, where Rf is a locally defined
parameter.
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o C-Type = 2, LINK_SUMMARY_ERROR
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ERROR CODE |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The following bit-values are defined:
0x01 = Unacceptable non-negotiable LINK_SUMMARY parameters
0x02 = Renegotiate LINK_SUMMARY parameters
0x04 = Bad Received Remote_Link_Id
0x08 = Bad TE Link Object
0x10 = Bad Data Link Object
All other values are Reserved.
Multiple bits may be set to indicate multiple errors.
This object is non-negotiable.
15. Security Considerations
Security is discussed in [LMP-SEC].
16. Intellectual Property Considerations
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication and any assurances
of licenses to be made available, or the result of an attempt made
to obtain a general license or permission for the use of such
proprietary rights by implementers or users of this specification
can be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
17. References
17.1. Normative References
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[RFC2026] Bradner, S., "The Internet Standards Process -- Revision
3," BCP 9, RFC 2026, October 1996.
[BUNDLE] Kompella, K., Rekhter, Y., Berger, L., "Link Bundling in
MPLS Traffic Engineering," Internet Draft, draft-
kompella-mpls-bundle-05.txt, (work in progress), February
2001.
[RFC2961] Berger, L., Gan, D., et al, "RSVP Refresh Overhead
Reduction Extensions," RFC 2961, April 2001.
[GMPLS-SIG] Ashwood-Smith, P., Banerjee, A., et al, "Generalized
MPLS - Signaling Functional Description," Internet Draft,
draft-ietf-mpls-generalized-signaling-06.txt, (work in
progress), October 2001.
[G707] ITU-T G.707, "Network node interface for the synchronous
digital hierarchy (SDH)," March 1996.
[GR253] GR-253-CORE, "Synchronous Optical Network (SONET)
Transport Systems: Common Generic Criteria," Telcordia
Technologies, Issue 3, September 2000.
[LMP-SEC] Ramamoorthi,S. and Zinin, A., "LMP Security Mechanism,"
Internet Draft, draft-sankar-lmp-sec-00.txt, (work in
progress), Internet Draft, February 2002.
17.2. Informative References
[LAMBDA] Awduche, D. O., Rekhter, Y., Drake, J., Coltun, R.,
"Multi-Protocol Lambda Switching: Combining MPLS Traffic
Engineering Control with Optical Crossconnects,"
Internet Draft, draft-awduche-mpls-te-optical-03.txt,
(work in progress), April 2001.
[RFC3209] Awduche, D. O., Berger, L, et al, "Extensions to RSVP
for LSP Tunnels," Internet Draft, RFC3209 December 2001.
[RFC3219] Jamoussi, B., ed., "Constraint-Based LSP Setup using
LDP," RFC3219, January 2002.
[OSPF-TE] Katz, D., Yeung, D., Kompella, K., "Traffic Engineering
Extensions to OSPF," Internet Draft, draft-katz-yeung-
ospf-traffic-04.txt, (work in progress), February 2001.
[ISIS-TE] Li, T., Smit, H., "IS-IS extensions for Traffic
Engineering," Internet Draft,draft-ietf-isis-traffic-
02.txt, (work in progress), September 2000.
18. Acknowledgements
The authors would like to thank Andre Fredette for his many
contributions to this draft. We would also like to thank Ayan
Banerjee, George Swallow, Andre Fredette, Adrian Farrel, Vinay
Ravuri, and David Drysdale for their insightful comments and
suggestions. We would also like to thank John Yu, Suresh Katukam,
and Greg Bernstein for their helpful suggestions for the in-band
control channel applicability. Finally, we would like to thank
Dimitri Papadimitriou for his contributions to the SONET/SDH test
procedures.
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19. Contributors
Jonathan P. Lang Krishna Mitra
Calient Networks Calient Networks
25 Castilian Drive 5853 Rue Ferrari
Goleta, CA 93117 San Jose, CA 95138
Email: jplang@calient.net email: krishna@calient.net
John Drake Kireeti Kompella
Calient Networks Juniper Networks, Inc.
5853 Rue Ferrari 385 Ravendale Drive
San Jose, CA 95138 Mountain View, CA 94043
email: jdrake@calient.net email: kireeti@juniper.net
Yakov Rekhter Lou Berger
Juniper Networks, Inc. Movaz Networks
385 Ravendale Drive email: lberger@movaz.com
Mountain View, CA 94043
email: yakov@juniper.net
Debanjan Saha Debashis Basak
Tellium Optical Systems Accelight Networks
2 Crescent Place 70 Abele Road, Suite 1201
Oceanport, NJ 07757-0901 Bridgeville, PA 15017-3470
email: dsaha@tellium.com email: dbasak@accelight.com
Hal Sandick Alex Zinin
Shepard M.S. Alcatel
2401 Dakota Street email: zinin@psg.com
Durham, NC 27705
email: sandick@nc.rr.com
Bala Rajagopalan
Tellium Optical Systems
2 Crescent Place
Oceanport, NJ 07757-0901
email: braja@tellium.com
20. Contact Address
Jonathan P. Lang
Calient Networks
25 Castilian Drive
Goleta, CA 93117
Email: jplang@calient.net
Lang et al [Page 65]