We are testing VOIP service.

a provider has set us up with a DID and 3 Call paths for a SIP trunk.

We have configured IT 5.2.13 settings with all relevant information provided by the VOIP provider. Upon saving the config to our MCP based OS7200 (running 4.46d), the SIP Service Available option changes to Yes. at this point we can send and receive calls using the service without any problems.

After a certain amount of time (about 10-15 minutes), we suddenly lose the ability to receive inbound calls. Any inbound call gets an operator message that the call cannot be completed as dialed. Outbound calls can still be placed without issue.

Furthermore, if we enter IT 5.2.13 and Disable the service and then immediately reenable, we once again regain the ability to send and receive, until an additional 10-15 minutes has passed.

Has anyone encountered this before?

Is this a problem with the provider or with our configuration?

I am doing some additional testing to determine if the inability to receive calls only happens if no incoming calls are received or if it just strictly X amount of time from the initial connection.

Any insight would be greatly appreciated.