Nortel Networks 3500 User Manual
Operation, administration, and maintenance (OAM) features 2-119
Planning and Ordering Guide—Part 1 of 2 NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004
•
Forced switch on working channel of a span. This switches traffic from the
working channels on a span to the protection channels around the ring.
working channels on a span to the protection channels around the ring.
•
Manual switch on a working channel of a span. This switches traffic from
the working channels on a span to the protection channels around the ring.
the working channels on a span to the protection channels around the ring.
In BLSR, squelching is the application of AIS-P to avoid misconnection when
the source node or the destination node for connection is involved in a node
failure, node isolation, or ring segmentation. Each node maintains a squelch
table which holds the source and destination ID for each working connection
that the node is terminating (adding/dropping) or passing through.
the source node or the destination node for connection is involved in a node
failure, node isolation, or ring segmentation. Each node maintains a squelch
table which holds the source and destination ID for each working connection
that the node is terminating (adding/dropping) or passing through.
For BLSR configurations, Site Manager does not display squelch maps.
Protection hierarchy
Switch requests are not preempted. When a higher priority switch request is
made, the lower priority switch request is dropped. If the higher priority switch
request is released, the lower priority switch request is not reestablished.
made, the lower priority switch request is dropped. If the higher priority switch
request is released, the lower priority switch request is not reestablished.
Note: An exception to this is in the case of a Lockout of a working in a
BLSR. The Lockout of the working optical interface pre-empts any
pending forced or manual switches.
BLSR. The Lockout of the working optical interface pre-empts any
pending forced or manual switches.
See
Table 2-27
Services protection priority
Services protection priority
Circuit pack
Protection priority
DS1 (1:N, revertive) (see Note)
• Lockout
• Forced
• Autonomous (equipment failure)
• Manual
DS3x3, DS3VTx12, DS3x12,
DS3x12e, EC-1x3, EC-1x12, DSM
DS1x84 TM
(1+1 nonrevertive)
DS3x12e, EC-1x3, EC-1x12, DSM
DS1x84 TM
(1+1 nonrevertive)
• Forced
• Autonomous (equipment failure)
• Manual
OC-3, OC-3x4, OC-12, OC-12x4,
OC-48, OC-192 (UPSR, VT1.5,
STS-1, STS-3c, STS-12c, STS-24c,
STS-48c, path nonrevertive)
OC-48, OC-192 (UPSR, VT1.5,
STS-1, STS-3c, STS-12c, STS-24c,
STS-48c, path nonrevertive)
• Forced
• Autonomous (path failures)
• Manual