Ericsson MINI-LINK TN R3 ETSI Technical Description page 52

MINI-LINK TN R3 ETSI
Figure 43
Performance data is collected and fault management is provided for unprotected
as well as protected E1 interfaces (that is the 1+1 E1 SNCP group). This gives
accurate information on the availability of network connections.
3.9.2.2 Ring Protection
Figure 44
The 1+1 E1 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.
An E1 connection entering a ring at one point and exiting at another point can
therefore be protected with a 1+1 E1 SNCP group configured at each end of
the connection. The traffic is transmitted in both directions of the ring and the
traffic is received from two directions at the termination point.
46
1+1 E1 SNCP group
Tx
Rx
Protected E1
Unprotected E1
1+1 E1 SNCP principle
Star
Network topologies
1+1 E1 SNCP group
Link or
sub-network
Unprotected E1
Ring
Tree
4/1555-CSH 109 32/1-V1 Uen B 2007-09-14
Rx
Tx
Protected E1
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