Specifications

5-16
Cisco ONS 15454 Installation and Operations Guide, R3.2
March 2002
Chapter 5 SONET Topologies
Bidirectional Line Switched Rings
Note Some or all of the following alarms display during BLSR setup: E-W MISMATCH, RING
MISMATCH, APSCIMP, APSDFLTK, BLSROSYNC. The alarms will clear after you
configure all the nodes in the BLSR.
Step 6 Complete Steps 2 – 5 at each node that you are adding to the BLSR.
Step 7 After you configure the last BLSR node, wait for the BLSR Ring Map Change dialog box to display (this
can take 10 – 30 seconds).
Note The dialog box will not display if SDCC Termination alarms (e.g., EOC) or BLSR alarms
(such as E-W MISMATCH and RING MISMATCH) are present. If an SDCC alarm is
present, review the DCC provisioning at each node; use the “Create the BLSR DCC
Terminations” procedure on page 5-13. If BLSR alarms have not cleared, repeat Steps 1 – 6
at each node, making sure each node is provisioned correctly. You can also following alarm
troubleshooting procedures provided in the Cisco ONS 15454 Troubleshooting and
Maintenance Guide.
Step 8 On the BLSR Ring Map Change dialog, click Ye s.
Step 9 On the BLSR Ring Map dialog box, verify that the ring map contains all the nodes you provisioned in
the expected order. If so, click Accept. If the nodes do not appear, or are not in the expected order, repeat
Steps 1 – 8, making sure no errors are made.
Step 10 Switch to network view and verify the following:
• A green span line appears between all BLSR nodes
• All E-W MISMATCH, RING MISMATCH, APSCIMP, DFLTK, and BLSROSYNC alarms are
cleared.
Step 11 Test the BLSR using testing procedures normal for your site. Here are a few steps you can use:
a. Run test traffic through the ring.
b. Log into a node, click the Maintenance > Ring tabs, and choose MANUAL RING from the East
Switch list. Click Apply.
c. In network view, click the Conditions tab and click Retrieve. You should see a Ring Switch West
event, and the far-end node that responded to this request will report a Ring Switch East event.
d. Verify that traffic switches normally.
e. Choose Clear from the East Switch list and click Apply.
f. Repeat Steps a – d for the West Switch.
g. Disconnect the fibers at one node and verify that traffic switches normally.
5.2.7 Upgrading From Two-Fiber to Four-Fiber BLSRs
Two-fiber OC-48 or OC-192 BLSRs can be upgraded to four-fiber BLSRs. To upgrade, you install two
OC-48 or OC-192 cards at each two-fiber BLSR node, then log into CTC and upgrade each node from
two-fiber to four-fiber. The fibers that were divided into working and protect bandwidths for the
two-fiber BLSR are now fully allocated for working BLSR traffic.