Nortel Networks OPTera Metro 3500 - Manual (Page 56)

2-18 Operation, administration, and maintenance (OAM) features
OPTera Metro 3500 Multiservice Platform NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004
Figure 2-5
BLSR ring switch example
EX1231p
W
P
2
3
Legend
Add/drop multiplexer
One fiber divided into
working and protection
bandwidth
W
P = Working traffic
= Protection traffic
W
W
W
W
P
P
4 3
1 2
P
P
W
W
P
P
W
W
P
P
W
W
W
W
P
P
4 3
1 2
P
Short path
SD/3/4/S/RDI
Long path
SD/3/4/L/idle
P
W
W
P
P
W
W
P
P