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Cisco ONS 15454 DWDM Reference Manual, R8.5
78-18343-02
Chapter 15 Management Network Connectivity
15.9.2 Configuring LMP
message back with the ControlChannelDown flag set. In either case, the node then stops sending
messages for this control channel. Before a control channel is taken down, there should be a backup
control channel in place that can be used to manage the data links.
• Non-graceful means that one of the nodes just stops sending messages. The other side would declare
a failure after the HelloDeadInterval, but would continue to send Hello messages to see if the control
channel will come back up.
15.9.2.2 TE Link Management
LMP ensures that links are grouped into TE links and that the properties of those links are the same at
both endpoints. This is called TE link management, or link property correlation.
Link property correlation is used to synchronize the TE link properties and verify the TE link
configuration. The link property correlation function of LMP aggregates one or more data links into a
TE link and synchronizes the properties of the TE link with the neighbor node. The procedure starts by
sending a LinkSummary message to the neighbor. The LinkSummary message includes the local and
remote Link Identifier, a list of all data links that make up the TE link, and various link properties. It is
mandatory that a LinkSummaryAck or LinkSummaryNack message be sent in response to the receipt of
a LinkSummary message, indicating agreement or disagreement with the link properties.
Note A maximum of 256 LMP TE links is supported.
15.9.2.3 Link Connectivity Verification
Link connectivity verification is not supported in this release, but might be supported in the future.
15.9.2.4 Fault Management
Fault management is particularly useful when the control channels are physically diverse from the data
links. It is used for rapid notification regarding the status of one or more TE-link data channels. The use
of fault management is negotiated as part of the TE link’s LinkSummary exchange. Data links and TE
link failures can be rapidly isolated and fault management supports both unidirectional and bidirectional
LSPs. Transparent devices are useful because traditional methods for monitoring the health of allocated
data links might no longer be appropriate. Instead, fault detection is delegated to the physical layer (for
example, loss of light or optical monitoring of the data) instead of Layer 2 or Layer 3. Fault management
uses the ChannelStatus, ChannelStatusAck, ChannelStatusRequest, and ChannelStatusResponse
messages.
Note The LMP Channel Activation/Deactivation Indication procedures are not supported; they are described
in the IETF LMP document, Sections 6.4 and 6.5.
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