12-26
Cisco ONS 15454 Reference Manual, R7.0
78-17191-01
Chapter 12 SONET Topologies and Upgrades
12.9 12.9.1 Unprotected Point-to-Point or Linear ADM to Path Protection
12.9.1 Unprotected Point-to-Point or Linear ADM to Path Protection
CTC provides a topology conversion wizard for converting an unprotected point-to-point or linear ADM
topology to path protection. This conversion occurs at the circuit level. CTC calculates the additional
path protection circuit route automatically or you can do it manually. When routing the path protection
circuit, you can provision the USPR as go-and-return or unidirectional.
When performing an in-service topology upgrade on a configuration with VCAT circuits, CTC allows
you to select member circuits to upgrade individually. When upgrading VT tunnels, CTC does not
convert the VT tunnel to path protection, but instead creates a secondary tunnel for the alternate path.
The result is two unprotected VT tunnels using alternate paths.
To convert from point-to-point or linear ADM to a path protection, the topology requires an additional
circuit route to complete the ring. When the route is established, CTC creates circuit connections on any
intermediate nodes and modifies existing circuit connections on the original circuit path. The number
and position of network spans in the topology remains unchanged during and after the conversion.
Figure 12-21 shows an unprotected point-to-point ADM configuration converted to a path protection. An
additional circuit routes through Node 3 to complete the path protection.
Figure 12-21 Unprotected Point-to-Point ADM to Path Protection Conversion
12.9.2 Point-to-Point or Linear ADM to Two-Fiber BLSR
A 1+1 point-to-point or linear ADM to a two-fiber BLSR conversion is manual. You must remove the
protect fibers from all nodes in the linear ADM and route them from the end node to the protect port on
the other end node. In addition, you must delete the circuit paths that are located in the bandwidth that
will become the protection portion of the two-fiber BLSR (for example, circuits in STS 25 or higher on
an OC-48 BLSR) and recreate them in the appropriate bandwidth. Finally, you must provision the nodes
as BLSR nodes.
To complete a conversion from an unprotected point-to-point or linear ADM to a two-fiber BLSR, use
the CTC Convert Unprotected/UPSR to BLSR wizard from the Tools > Topology Upgrade menu.
115716
Node 1 Node 2
Node 1
Node 3
Node 3
Node 2