Ericsson MINI-LINK TN R4 ETSI Technical Description page 58

Technical Description
Figure 43
Performance data is collected and fault management is provided for
unprotected as well as protected VC4, VC3 or VC12 interfaces (that is the
1+1 VC SNCP group). This gives accurate information on the availability of
network connections.
3.10.2.3 Ring Protection
Figure 44
The 1+1 SNCP mechanism described in the previous section can be used to
create protected ring structures in the microwave network. In a ring topology, all
nodes are connected so that two nodes always have two paths between them.
A connection entering a ring at one point and exiting at another point can
therefore be protected with a 1+1 SNCP group configured at each end of the
54
1+1 VC SNCP group
Tx
Rx
Protected VC
Unprotected VC
1+1 VC SNCP principle
Star
Network topologies
1+1 VC SNCP group
Link or
sub-network
Unprotected VC
Ring
Tree
12/221 02-CSH 109 32/1-V1 Uen A 2008-03-14
Rx
Tx
Protected VC
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