Technical Handbook Common Alcatel 1850 Tss-320 Rel - Alcatel 1850 TSS-320 Technical Handbook

An example of 2F MS-SPRING is reported in Figure 79.on page 130.
In the example a ring of four nodes is protected with 2F MS-SPRING
AU4-1 carries the traffic of the span: C-B, B-A, A-D, D-C
AU4-2 carries the traffic of the span D-B (pass-through in C)
AU4-9 protects AU4-1.
AU4-10 protects AU4-2.
After a failure in the section C-B, the following actions are performed on :
– node B:Streams access 1 and 2, previously drop-inserted on AU4-1 and AU4-2 "side
A", are switched respectively on AU4-9 and AU4- 10 "side B".
– node C:Stream access 1, previously drop-inserted on AU4.1 "side B", is switched on
AU4-9 "side A".
– nodes A and D do not switch
We can obtain from the example that is possible bandwidth re-used for some traffic patterns (AU4-9
protects four connection on AU4-1) having the same protection for some several connections (shared
protection).
Technical Handbook Common
Functional Description
In this way, C is reached through nodes A and D.
In this way, B is reached through nodes D and A.
Rx AU4-2 "side A", previously in pass-through on Tx AU4-2 "side B", is looped
on Tx AU4-10 "side A". In this way, B is reached through nodes D-A (signal
transmitted D to B).
Rx AU4-2 "side B" is no more received.
So, Rx AU4-10 "side A" is looped on the Tx AU4-2 "side A".
In this way, the signal transmitted by node B follows the path:
A-D- C and here is looped to reaches node D again.
Alcatel 1850 TSS-320 Rel. 1.1
8DG 07734 AAAA Edition 01 129/270