CCM 5.1.1 at center office, two remote sites have Cisco 2821 with T1/PRI configured with standard SRST in one site, and CME-srst in another site. IOS is ipvoice 12.4(15)T1.
When wan is down, the inbound/outbound calls for ip phones can work fine as expeected; while when WAN is up, from both voice gateways, we saw the gateways are still in fallback mode, even I issued "no mgcp" and "mgcp", while on CCM webpage, it shows the voice gateway are registered. but inbound/outbound calls can not go through.
The only work around for me at this moment is that we reboot the voice gateways when WAN is up, then both voice gateways are registered to CCMs and all calls can go through.
Is there anyone experenced this problem of SRST router stucks in fallback mode and how to solve the problem?