Cisco ONS 15327 User Documentation page 442

Alarm Procedures
A procedural error misconnect east/west direction (E-W-MISMATCH) alarm occurs when nodes in a
ring have an east slot/port misconnected to another east slot/port or a west slot/port misconnected to
another west slot/port. In most cases, the user did not hook up the fibers correctly, or the ring
provisioning plan was flawed. You can physically reconnect the cable to the correct slot/ports to clear
the E-W-MISMATCH alarm. Alternately, you can delete and recreate the span in CTC to change the west
line and east line designations. The CTC method clears the alarm, but may change the traditional
east-west node connection pattern of the ring.
The E-W-MISMATCH alarm also appears during the initial set up of a ring with its East-West slot/ports
Note
configured correctly. In this instance, the alarm clears itself shortly after the ring setup is complete.
The lower-numbered slot on a node is traditionally labelled as the west slot and the higher numbered slot
Note
is labelled as the east slot. For example, Slot 6 is west and Slot 12 is east.
Procedure: Clear the E-W-MISMATCH Alarm with a Physical Switch
Step 1 Diagram the ring setup, including nodes and spans, on a piece of paper or white board.
Display the CTC network view and label each of the nodes on the diagram with the same name that
Step 2
appears on the window network map.
Double-click each span to reveal the node name/slot/port for each end of the span.
Step 3
Step 4 Label the span ends on the diagram with the same information. For example, with Node1/Slot12/Port1
- Node2/Slot6/Port1 (2F BLSR OC48, Ring ID=0), label the end of the span that connects Node 1 and
Node 2 at the Node 1 end as Slot 12/Port 1. Label the Node 2 end of that same span Slot 6/ Port 1.
Step 5 Repeat Steps 3 and 4 for each span on your diagram.
Step 6 Label the highest slot at each node east and the lowest slot at each node west.
Look at the diagram. You should see a clockwise pattern of west slots connecting to east slots for each
Step 7
span.
If any span has an east-to-east or west-to-west connection, physically switch the fiber connectors from
Step 8
the card that does not fit the pattern to the card that continues the pattern. This should clear the alarm.
Note
Procedure: Clear the E-W-MISMATCH Alarm with the CTC
Login to the misconnected node. This is the node with both ring fibers misconnected; it is in the middle
Step 1
of the two nodes that have one of two ring fibers misconnected.
Click the Provisioning > Ring tabs.
Step 2
Cisco ONS 15327 User Documentation, R3.3
14-34
The above physical switch procedure is the recommended method of clearing this alarm. This
method reestablishes the logical pattern of connection in the ring. However, you can also use
CTC to recreate the span and identify the misconnected slot/ports as east and west. This is useful
when the misconnected node is not geographically near the troubleshooter.
Chapter 14 Alarm Troubleshooting
June 2002