Configuring The Deroute Delay - Cisco MGX 8850 (PXM1E/PXM45) Configuration Manual

Chapter 8 Managing PNNI Nodes and PNNI Routing

Configuring the Deroute Delay

The deroute delay feature establishes a wait time between the time when the switch detects an interface
failure and the time when connections are released (derouted). This feature provides time for the
condition that caused the interface failure to recover. If the interface recovers, an unnecessary deroute is
avoided. If the interface does not recover by the end of the deroute delay, all connections on that interface
are derouted.
A separate deroute delay applies to each interface. By default, the deroute delay is disabled. When
configuring a deroute delay, consider the following guidelines:
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Note
To change the deroute delay, enter the cnfpnportloscallrel command as follows:
PXM1E_SJ.7.PXM.a > cnfpnportloscallrel <portid> <yes|no> [-delay <time>]
Enter the portid in the format: [shelf.]slot[:subslot].port[:subport]. To display the port numbers, enter
the dsppnports command.
To enable the deroute delay and configure a delay period, enter yes after the portid and enter the -delay
option with a time in the range of 1 to 59 seconds. The parameter following the portid is the loss of signal
(LOS) call release parameter. When this parameter is set to yes, a LOS releases the call after any
configured deroute delay. When this parameter is set to no, the call is released upon a Service Specific
Connection Oriented Protocol (SSCOP) reset, which is controlled by the SSCOP timers.
To disable the deroute delay, enter the -delay option with the time set to 0 seconds.
Release 5.0.10, OL-3845-01 Rev. B0, August 16, 2004
When deroute delay is enabled and a port goes into provisioning mode (due to card removal or a
partition deletion), the end being provisioned will release the connections. The other end will detect
LOS and hold the connections for the deroute delay period.
For the deroute delay feature to operate correctly, both ends of a trunk must use the same deroute
delay configuration. If a third party switch does not support deroute delay, this feature should be
disabled on Cisco MGX switch interfaces that connect to the third party switch.
For the deroute delay feature to work, the ILMI Secure Link Procedures feature should be disabled
on the port using the cnfilmiproto command. Otherwise, the release initiation will start as soon as
the ILMI protocol resets. Note that there is no impact on PNNI NNI interfaces when the ILMI Secure
Link Procedures feature is disabled.
If a continuity check (CC) is enabled on a connection when the host interface fails, an AIS signal
will be sent to the CPE, regardless of the deroute delay or AIS delay configuration. When using
deroute delay or AIS delay on a host interface, disable CC (cnfcon command) on all connections
that use that interface.
If you configure deroute delay on an AXSM-E or an AXSM-XG NNI interface, you must disable
AIS generation on the interface using the cnfatmln command.
There is a special case where disabling AIS generation can create problems. If you configure an
IMA group, we recommend that you configure all ports on that IMA group as either UNI or NNI
ports. If you configure an IMA group with a mix of UNI and NNI ports, and then you disable
AIS generation, AIS generation will be disabled for both UNI and NNI ports. We recommend
that you do not disable AIS on UNI ports.
Cisco MGX 8850 (PXM1E/PXM45), Cisco MGX 8950, Cisco MGX 8830, and Cisco MGX 8880 Configuration Guide
Managing PNNI Routes
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