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Cisco ONS 15454 Installation and Operations Guide
78-13453-01
Chapter5 SONET Topologies
Bidirectional Line Switched Rings
Step 7 Use information recorded in Step 1 to switch traffic away from the ports of ne i ghboring nodes that will
be disconnected when the node is removed:
Caution Traffic is unprotected during the protection switch.
a. Open the neighboring node that is connected through its east port to the removed node.
b. Click the Maintenance > Ring tabs.
c. From the East Switch list, choose FORCE RING. Click Apply.
d. Open the node that is connected through its west port to the removed node.
e. Click the Maintenance > Ring tabs.
f. From the West Switch list, choose FORCE RING. Click Apply.
Step 8 Remove all fiber connections between the node being removed and the two neighboring nodes.
Step 9 Reconnect the two neighboring nodes directly, west port to east port.
Step 10 Close CTC, then log into a node on the reduced ring.
Step 11 Wait for the BLSR Map Ring Change dialog box to display. (If the dialog box does not display after
10 – 15 seconds, select the Provisioning > Ring tabs and click Ring Map.) When the dialog box
displays, click Yes .
Step 12 On the BLSR Ring Map dialog box, click Accept.
Step 13 Clear the protection switches on the neighboring nodes:
a. Open the node with the protection switch on its east port.
b. Click the Maintenance > Ring tabs and choose CLEAR from the East Switch list. Click Apply.
c. Open the node with the protection switch on its west port.
d. Click the Maintenance > Ring tabs and choose CLEAR from the West Switch list. Click Apply.
Step 14 If a BITS clock is not used at each node, check that the synchronization is set to one of the eastbound or
westbound BLSR spans on the adjacent nodes. If the removed node w as t he B IT S ti ming sourc e, u se a
new node as the BITS source or select internal synchronization at o ne no de whe re a ll oth er no de s wi ll
derive their timing. (For information about ONS 15454 timing, see the “Sett ing Up ONS 15454 Timing”
section on page 3-12.)
5.2.8 Moving BLSR Trunk Cards
Caution Call the Technical Assistance Center (1-877-323-7368) before per formi ng thi s proce dur e t o en sure
that circuit and provisioning data is preserved.
Caution To change BLSR trunk cards, you will drop one node at a time from the current BLSR. This
procedure is service affecting during the time needed to complete the steps below. This applies to all
BLSR nodes where cards will change slots. Review all the steps before you proceed.