This chapter provides information and sample procedures for setting up STS or VT circuits over existing path protection and bidirectional line switch ring (BLSR) configurations using TL1, including 1-way drop and continue.
Note The terms "Unidirectional Path Switched Ring" and "UPSR" may appear in Cisco literature. These terms do not refer to using Cisco ONS 15xxx products in a unidirectional path switched ring configuration. Rather, these terms, as well as "Path Protected Mesh Network" and "PPMN," refer generally to Cisco's path protection feature, which may be used in any topological network configuration. Cisco does not recommend using its path protection feature in any particular topological network configuration.
Note Because the ONS 15454/ONS 15327 implements logical path protection, there are no defined east and west ports. Instead, the east STS path for one circuit can exit a different port than the east STS path of another circuit, even though the west STS paths for both circuits may share the same port.
5.1 1-Way Drop and Continue
The following examples show how to create a 1-way drop and continue cross-connect. The examples use three nodes (Node 1, Node 2, and Node 3) in a ring configuration (Figure 5-1). Node 1 is the source node, Node 2 has the drop and continue, and Node 3 is the destination.
Figure 5-1 1-way drop and continue
Figure 5-2 shows a circuit diagram example of the orientation of AIDs associated with the ENT-CRS command used to establish drop and continue connections.
Figure 5-2 Orientation of AIDs used to establish drop and continue connections
5.1.1 Sample Node 1 Configuration (Source Node)
Issue the ENT-CRS-STSn::STS-1-1,STS-5-1&STS-6-1:CTAG::1WAY; command on Node 1.
Figure 5-3 Bridge from 1/1/1 to 5/1/1 and 6/1/1
5.1.2 Sample Node 2 Configuration (Drop and Continue Node)
Issue the ENT-CRS-STSn::STS-5-1&STS-6-1,STS-1-1:CTAG::1WAYDC; on Node 2.
Figure 5-4 Selector between 5/1/1 and 6/1/1 to 1/1/1
5.1.3 Sample Node 3 Configuration (Destination Node)
Issue the ENT-CRS-STSn::STS-5-1&STS-6-1,STS-1-1:CTAG::1WAY; on Node 3.
Figure 5-5 Selector between 5/1/1 and 6/1/1 to 1/1/1