Difference between telephony-service and call-manager-fallback 1

[preetss]

Hi all,
I want to know the exact difference between the telephony-service and call-manager-fallback.

Thanks,
Uday

 

[whykap]

telephony service is used for call manager express,
call manager fallback is used in SRST mode.

 

[kcbell]

preetss:

Telephone service is when your remote site is talking with your call manager and getting instruction from the Call Manager - life is good!

Fallback is the remote site router cannot talk to the Call Manager because the VPN or WAN is down. Therefore the router is fall back to SRST mode. Go to Cisco to find what function your remote site can do during this mode. I know the remote site can dial 911 for sure as well as it can receive incoming call as well. When it is in SRST mode, if you are in the "home" site, you cannot call them via the four digit dialing - if you use four digits dialing. They cannot call you either.

I ran into SRST mode recently in a remote site. The WAN came back but the phone was still in SRST mode. The way to fix the problem was to upgrade the remote site gateway router to be compatible with the Call Manager. It was ugly!

Hope this help!