Nortel Networks OPTera Metro 3500 - Manual (Page 66)

2-28 Operation, administration, and maintenance (OAM) features
OPTera Metro 3500 Multiservice Platform NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004
Figure 2-13
OC-192 BLSR node failure example
EX1497p
Ring ADM
C-D C-B
C
D-B
D-A
A-D A-B
A
(Add-drop)
D
B-D
B-A
B
Fiber 1
Fiber 2
= Working STS-1 timeslots (1 through 96)
= Protection STS-1 timeslots (97 through 192)
Legend:
= Single fiber cable with 96 working
and 96 protection timeslots
Node
failure
Bridge
(B-D)
B-C (AIS)
D-C (AIS)
= Alarm indication signal AIS