Cannot Call Between Subscribers - CUCM

[R M]

I have a really strange issue. I have two subscribers that cannot call devices registered on each other. They can call devices registered on other subscribers, and other subscribers can call them. They just can't call each other. When attempting to call a phone registered on one of the subscribers, calls ring to voice mail (following the Forward Unregistered Internal setting on the DN). If I disable Forward Unregistered Internal, I get a fast busy.

dbreplication is showing healthy. I restarted the RIS Data Collector service, without improvement.

Has anyone ever seen this behavior before?

[Jaime Valencia · Accepted solution]

It seems the SDL layer might not be in good state, you can try a cluster reboot.

[R M]

Thanks! After noticing SDLLinkOOS (SDL Link Out of Service) in the traces and RTMT, I restarted the subscriber the errors were pointing to. Everything is working swell now.

[Abhay Singh Reyal]

Try to ping effected subscribers from the CLI of subs and see if there is any packet drop. Also you can have a look at the traces for a test call. 

Regards

Abhay Reyal