Cisco IP Phone 7940: HTTP Error [400]! with Extension Mobility

[SamSaul]

Hi there, 

We upgraded Cisco CUCM from 9.1 to 11.5.2. We have around 40 Cisco IP Phone 7940. On a couple of phones when users try to log in - using Extension Mobility - they get an error "HTTP Error [400]!". Most of Cisco IP Phone 7940 don't have this issue. IP addresses are used every where (CUCM Server, Enterprise Parameters, Extension Mobility etc). All the phones got the same firmware.

Please advise. 

Regards, 

Sam 

[SamSaul · Accepted solution]

I found the solution. If phones don't support Extension Mobility Cross Cluster, it will get this error message. 

Example:

http://123.45.67.89:8080/emapp/EMAppServlet?device=#DEVICENAME#

Note

If you append the Extension Mobility Cross Cluster suffix &EMCC=#EMCC#in the service URL for Extension Mobility, the Extension Mobility login fails with an HTTP 400 error on phones that do not support Extension Mobility Cross Cluster. Users will see a blank screen on the phone when the Extension Mobility service is not selected.

[RITR]

We upgraded from 11.5 to 12.0 and it tacked on the &EMCC=#EMCC# part for some reason. We removed it and it worked again.

http://CMPUB:8080/emapp/EMAppServlet?device=#DEVICENAME#&EMCC=#EMCC#

[Richard McLoughlin]

Thanks every one who o contributed to this thread - this helped me out a lot when we ran into the same issue following an upgrade from 11.0(1)SU1 to 11.5(1)SU4.

At the risk of teaching you all to suck eggs, just one additional piece of advice so that you don't make the same error I did:- Once you amend the service urls, don't forget to click the "update subscriptions" button to push to change out to your telephony end points.  

Initially we got involved in unsubscribing and re-subscribing phones and users to EM which does work but doesn't scale well as a work around ;-).

All the best

Rich

[Richard McLoughlin]

Juste a note to the wise:- I've just upgraded again from 11.5(1) SU4 to 11.5(1) SU10 and the "&EMCC=#EMCC#" got appended again so the 7940/7960  HTTP Error [400!] issue re-occurred. The resolution is the same. Don't forget to "Update Subscriptions" afterwards.

Rich

[ANDREA LOPEZ]

After removing the &EMCC=#EMCC# at the end of the service URL, do any services need restarting?

[Richard McLoughlin]

Hi Andrea



No it shouldn't be necessary (I tried it and it didn't resolve the issue). What you need to do is update your subscriptions by going to Cisco Unified CM Administration - Device - Device Settings - Phone Services - find and select the extension mobility service and select "Update Subscriptions". It takes a while depending on how many phones you have.



Hope that helps



Rich