Imagine I have this scenario:
CLients&IP-Phones(non Cisco)---Layer2Switch-----Router2821------WANLink----Provider(IP Centrex Solution, Call Control hosted in the cloud service provider).
Let's say WAN Link goes down.
Can IP phones still make internal phone calls successfully?
I was told by competitor, that using their router, the device will act as a SIP Proxy and thus IP Phones will register with WAN-Router. Thus internal phone calls are operational. Competitor states that with Cisco routers such feature is not possible. Note that IP phones are non Cisco.
Can someone clarify that for me?