SIP Phone registration with CME with Logged out extension

[ravi ahuja]

Hello Experts

I need your views/ suggestion on the below explained setup as I am unable to setup the same in my LAB due to n/w issue

Setup

Sip Phone - 7841

Logged out extension - 2122244

EM Extension - 6022244

CME/ SRST - ISR 3945

CUCM - 10.5

CME is configured for SIP phones and the same logged out  extension ( 2122244 )is hardcoded against the 7841 MAC address.

My question/ concern here is that when the user is logged in on 7841 phone  using an EM profile and all of a sudden the SRST kicks in, will the phone register to the CME with the EM extension as the logout doesn't happens or will the phone get the configuration from the CME.

Previous Observation - When 7942/6941 were configured as SIP phone, the phone was unable to get the hardcoded extension displayed as the SRST kicked in.

I am in process of testing but the requirement is quite urgent, so incase some one can help me with the past experience on this setup or can do a test up, that will be a great help.

Thanks

[R0g22]

Do you have SRST or CME-as-SRST configured ? With SRST, phones do not get config file from the SRST router.

[ravi ahuja]

CME as SRST.

[HARIS_HUSSAIN]

It will load with the Extension which it currently have, but EM is not supported in SRST so login logout features will not work.

https://www.cisco.com/c/en/us/products/collateral/unified-communications/unified-survivable-remote-site-telephony/prod_qas0900aecd8028d113.html
Does Cisco Unified SRST/E-SRST support Extension Mobility?
A. Cisco Unified SRST/E-SRST routers do not support Extension Mobility. IP phones rely on the support from Cisco Unified Communications Manager for Extension Mobility support. When in SRST mode, IP phones fall back to the SRST router with whatever profile it contains (extension#... etc.).

If possible Please share your SRST Config for second query.