5-11
Cisco ONS 15454 Installation and Operations Guide
November 2001
Chapter5 SONET Topologies
Bidirectional Line Switched Rings
•Create the BLSR DCC terminations. See the “Create the BLSR DCC Terminations” procedure on
page 5-13.
•Enable the BLSR ports. See the “Enable the BLSR Po rts” proced ure on page 5-13.
•Set up BLSR timing. See the “Set up ONS 15454 Timing” procedure on page3-14 .
•Provision the BLSR. See the “Provision the BLSR” procedure on page5-14.
Procedure: Install the BLSR Trunk Cards
Step 1 Install the OC-12, OC-48, OC-48AS, or OC-192 cards that will serve as the BLSR trunk cards. You can
install the OC-12 and OC-48AS cards in any slot, but you can install the OC-48 and OC-192 cards only
in Slots 5, 6, 12, or 13.
Step 2 Allow the cards to boot.
Step 3 Attach the fiber to the east and west BLSR ports at each node.
Plan your fiber connections and use the same plan for all BLSR nodes. For example, make the east port
the farthest slot to the right and the west port the farthest left. Plug fiber connected to an east port at one
node into the west port on an adjacent node. Figure 5-11 shows fiber connections for a two-fiber BL SR
with trunk cards in Slot 5 (west) and Slot 12 (east).
Note Always plug the transmit (Tx) connector of an OC-N card at one node into the receive (Rx)
connector of an OC-N card at the adjacent node. Cards will display an SF LED if Tx and Rx
connections are mismatched.
For four-fiber BLSRs, use the same east - west connection pattern for th e working and prot ect fiber s. Do
not mix working and protect card connections. The BLSR will not function if working and protect cards
are interconnected. Figure 5-12 shows fiber connections for a four-fiber BLSR. Slot 5 (west) and Sl ot
12 (east) carry the working traffic. Slot 6 (west) and Slot 13 (east) carry the protect traffic.