We have a Call Manager and routers with SRST loaded. When the link to the CM goes down, Router "A" with SRST is to provide dial tone to the phones connected to Router "A". However, when the link goes down to the CM, another Router "B" who is spoked behind Router "A" (different physical location) needs to maintain dial tone service. The customer wants Router "A" and Router "B" SRST IP Phones to be able to call each other when the uplink to CM is down. Note there is connectivity betweeen Router "A" and Router "B" when the uplink to the CM is down.
Is the possible? We have no other hardware except 3845 and 2811 v12.4(3g)routers in the mix. CM is v4.2. SRST is v3.3.