Cisco Cisco ONS 15600 Multiservice Switching Platform (MSSP)

When you perform a Manual Switch To Protect and then an SD-L condition is raised on the Protect port 
that preempts the Manual Switch To Protect, the CTC Maintenance > Protection tab shows 
“APS_CLEAR.” When you click Clear in that tab while the SD-L is still present on the protect port, the 
K bytes will change to “No Request” for about 400-1000 frames before redeclaring the SD-L condition. 
This issue can occur on ONS 15600 ASAP cards with 1+1 protection. It does not affect other cards or 
protection schemes. This issue does not affect traffic. This issue can only occur when using the CTC 
Maintenance > Protection tab under the aforementioned conditions. To avoid this issue, do not click 
Clear when the CTC Maintenance > Protection tab shows “APS_CLEAR” and SD-L is present on the 
protect port. This issue will be resolved in a future release.

A CTC client session can disconnect from an ONS node during simultaneous deletion of large numbers 
of VT level circuits (3000+). Connectivity to the node will recover without any user action. If the 
condition persists, restart the CTC session to reconnect. This issue is under investigation.

ONS platforms support only a single OSPF virtual link. This issue will be resolved in a future release.

Network connectivity could be lost if a backbone area becomes segmented into multiple GNEs. This 
occurs only if multiple ONS 15600 nodes and routers are connected to the same LAN in OSPF area 0. 
If a link between two routers breaks, the CTC session connected to Router 1 will not be able to 
communicate with the ONS 15600 connected to Router 2. To resolve, you must repair the link between 
the routers or provide another form of redundancy in the network. This is as designed.

If OSPF on LAN is enabled with an area ID that is the same as the area ID of any of the DCC Links, 
CTC will not be able to discover any of the DCC Connected Nodes. To avoid this issue, set the OSPF on 
LAN area ID to an area other than any of those already occupied by a DCC link. This is as designed.

Equipment alarms are always reported based on the activity of the particular card, without taking card 
redundancy into consideration. Thus, an equipment alarm such as CTNEQPT-PB-0 may be raised against 
a line card as CR(SA) even though the traffic is protected. This issue will not be resolved.

Choosing certain qualities of RES settings in the CTC Provisioning tab, Timing subtab, may trigger a 
reference failure. Specifically, this can occur if you select the quality of RES level such that any of the 
following are true.

ST3 < RES < ST3E

ST4 < RES < SMC