CUCM 8.5 Extension Mobility resilience

[Chris Bailey]

I have a CUCM 8.5 Cluster with pub and 4 subs

Extension Mobility is currently using the pub. 

The extension mobility services URL is pointing to the IP address of the publisher. 

I'm having sleepless nights that if the publisher goes down we will have no extension mobility services. 

What options do I have for resilience? 

If I start the extension mobility services on one of the subs and create a new service called "Extension Mobility DR" and point the URL to the IP address of the subscriber will this work if the publisher goes down? 

[Jaime Valencia]

Yes, that is an option, the SRND discusses EM HA

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/8x/uc8x/cmapps.html#wp1189079

[Chris Bailey]

I just tried this and it didn't work.

I have EM service started on the Pub and Sub

I created the Extension Mobility DR service URL pointing to the Sub IP and I subscribed to this DR service on my test phone and verified it worked.

I then disconnect the NIC for the Pub to simulate an outage but when I tried the Extension Mobility DR it just stuck on "Requesting"...

This is CUCM 8.5 

Anyone got this to work? 

[Deepak Mehta]

Hi Chris,

There is EM application  service on the network services (serviceability page) which also needs to be turnedon along with the EM services.Both needs to be on as they work in conduction with each other  while you are doing failover. Also can you set service provisioning to both in enterprise parameters rather then  internal which is default.thanks

[Chris Bailey]

Hi Deepak,

Thanks for this info - I just checked and the extension mobility application service under network services is running on all nodes. 

Should EM work if the publisher is down on 8.5? 

[Deepak Mehta]

Yes, it does looks like it is possible for 8.5 as per the documentation.

EM is a user-facing feature, and database writes pertaining to EM can be performed by subscriber nodes. Therefore, if the Unified CM publisher is unavailable, EM logins and logouts are still possible. Although I have personally tested this on 9.1 (using ACE load balancer). have you tried resetting the phone ?

[Chris Bailey]

With the publisher is up I can login using the EM service on the sub - I've confirmed using wireshark that its using the sub IP rather than the Pub IP. 

As soon as I disconnect the pub then the phone stays on requesting after I select the EM service. 

Anyone got this working?