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Cisco ONS 15454 Reference Manual, R7.0
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Chapter 12 SONET Topologies and Upgrades
12.9 12.9 In-Service Topology Upgrades
Procedures for manual span upgrades can be found in the “Upgrade Cards and Spans” chapter in the
Cisco ONS 15454 Procedure Guide. Five manual span upgrade options are available:
• Upgrade on a two-fiber BLSR
• Upgrade on a four-fiber BLSR
• Upgrade on a path protection
• Upgrade on a 1+1 protection group
• Upgrade on an unprotected span
12.9 In-Service Topology Upgrades
Topology upgrades can be performed in-service to convert a live network to a different topology. An
in-service topology upgrade is potentially service-affecting, and generally allows a traffic hit of 50 ms
or less. Traffic might not be protected during the upgrade. The following in-service topology upgrades
are supported:
• Unprotected point-to-point or linear ADM to path protection
• Point-to-point or linear ADM to two-fiber BLSR
• path protection to two-fiber BLSR
• Two-fiber to four-fiber BLSR
• Node addition or removal from an existing topology
You can perform in-service topology upgrades irrespective of the service state of the involved
cross-connects or circuits; however, a circuit must have a DISCOVERED status.
Circuit types supported for in-service topology upgrades are:
• STS, VT, and VT tunnels
• Virtual concatenated circuits (VCAT)
• Unidirectional and bidirectional
• Automatically routed and manually routed
• CTC-created and TL1-created
• Ethernet (unstitched)
• Multiple source and destination (both sources should be on one node and both drops on one node)
You cannot upgrade stitched Ethernet circuits during topology conversions. For in-service topology
upgrade procedures, refer to the “Convert Network Configurations” chapter in the Cisco ONS 15454
Procedure Guide. For procedures to add or remove a node, refer to the “Add and Remove Nodes” chapter
of the Cisco ONS 15454 Procedure Guide.
Note A database restore on all nodes in a topology returns converted circuits to their original topology.
Note Open-ended path protection and DRI configurations do not support in-service topology upgrades.
