We have several 7100's out there on v5.01 with SIP trunks. What I'm finding is that if the internet connection to the customer is dropped for a period of time, even when the outside internet is restored - the SIP trunk will not re-register. The customer will call me and I'll log into the system at 5.2.13 and change from Enable to Disable, then save. Wait a few seconds and change from Disable to Enable.

The trunk will register within about 20 seconds and will be fine again - until internet drops and comes back up and the same issue presents again.

Thanks