I wanted to see if you guys can give me idea where this issue might be arising from.
We have Comcast as our internet service provider in the office. We use a company called GPhone to provide us with our SIP trunk. For our hardware we have a German phone system called Innovaphone. We use the same hardware with different providers in many countries without any issues.
Every once a week or twice a week (actually just randomly) we have issues receiving calls. The system shows as if everything is running OK but we can not receive call from an external number. We are able to call within the office and we can even call external numbers but can not receive incoming calls when the error occurs. The problem is that our technician in Europe says that he sees nothing on the logs and Comcast says everything is perfect on their side. I am still waiting on a response from GPhone. The only thing we can do is to disable the SIP on our system and then enable it again for it to start working correctly. It seems as if there is an error and the connection to the SIP is not established automatically. The problem is that we do not receive any errors so we do not know the phones are down until someone is informed that the calls cant go in.
I wanted yo know if anyone has any idea what could be the issue? I don't know if the issue can be through the provider of the SIP Trunk, the hardware, or ISP. Any suggestion will be really appreciated.