Nortel Networks 3500, NTRN10AN manual Upsr planning guidelines summary, General guidelines

Operation, administration, and maintenance (OAM) features 2-189

UPSR planning guidelines summary

This section summarizes guidelines for STS-managed OPTera Metro 3500 and OPTera Metro 3000 UPSR configurations.

General guidelines

•Always consider current and future traffic requirements when designing a network.

•Always consider “A-Z” traffic in terms of logical rings. Note that UPSR logical rings start and end at the path bridge and select points.

Physical subtending rings

•If your subtending ring application does not use OPE circuit packs or shared VT-managed STS:

—Keep your logical UPSR ring small. Use a UPSR path selector on STS-managed OPTera Metro 3500 for traffic entering STS-managed OPTera Metro 3500 (not for traffic that originates and terminates on the same subtending ring).

•If your subtending ring application uses shared VT-managed STS:

—Evaluate your bandwidth requirements. If possible, eliminate the shared VT-managed STS and instead dedicate STS at each site. See Figure 2-63 on page 2-176for an example.

—If you cannot dedicate STS at each site, do not use a UPSR path selector on the shared VT-managed STS. Extend your shared STS as larger logical rings towards a node capable of terminating the UPSR path (use STS-managed OPTera Metro 3500 as a passthrough node only). See Figure 2-65 on page 2-178for an example.

—If you cannot dedicate STS at each site or extend the logical ring, your application might not be suited for a subtending ring. Consider using a collocated head-end ring connection.

Virtual rings across the STS-managed OPTera Metro 3500 backbone network

In a logical UPSR that spans a physical UPSR/BLSR/UPSR configuration (also referred to as a virtual ring), the UPSR protection path is also routed on BLSR working time slots. See Figure 2-65 on page 2-178for an example.

VT grooming at an STS-managed OPTera Metro 3500 site

An OPTera Metro 3000 NE collocated at an STS-managed OPTera Metro 3500 site can be used to groom VTs in order to optimize bandwidth utilization across the STS-managed OPTera Metro 3500 backbone network.

The collocated OPTera Metro 3000 NE can use dedicated STS at each site or shared VT-managed STS. See Figure 2-70 on page 2-185for an example of dedicated STS at each site. See Figure 2-71 on page 2-187and Figure 2-72 on page 2-188for examples of shared VT-managed STS.

Planning and Ordering Guide—Part 1 of 2 NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004