I'm trying to fully understand the subtleties of "SRST" and "MGCP Gateway Fallback" and would like to ask if I've got these concepts right in my head...
I'm thinking of "MGCP Gateway Fallback" commands:
GW(config-app-global)#service alternate default
As I understand it this basically says to any dial-peer that has "application mgcpapp" in it that if the gateway loses the link to CM then that dial-peer should be taken over by the "default" application (which seems to be H323???)
So is it correct to thinks of "MGCP Gateway Fallback" as just providing the very basic functionality to get a MGCP controlled gateway out to the PSTN if the WAN fails?
I'm thinking of SRST as providing all the other functionality you would want if the WAN link fails in that it allows the local IP phones to register to the gateway, can provide basic conferencing, call forwarding, and call transfer type functions.
If my thinking is correct does this not imply that (at least for MGCP) I would have to use both MCGP Gateway Fallback together and SRST? (ie: If I just enable SRST and not MGCP Gateway Fallback no external calls will be able to get in or out from the PSTN?)
Can someone tell me if I have this right?