GXP2130 and Voip.ms - no inbound calls


I have a GXP2130 phone configured on a voip.ms subaccount for outbound calls. I also have a DID registered at voip.ms, which I have pointed to the correct sub-account for the GXP2130. I can make outbound calls without any problem, but I cannot receive inbound calls. The server at voip.ms for the DID, and the server the phone is registered on, are the same. If I direct the DID to a Yealink phone, the phone rings immediately, but if I redirect the DID back to the GXP2130, it won’t ring. Nothing happens, no busy signal, nothing. It won’t even drop the call, just dead silence. If I redirect the DID to another grandstream GXP16xx series at a completely different location, the same behaviour, the call does not go through.

What am I missing on the configuration of these Grandstream phones? voip.ms tells me the problem is with the configuration of the phone, and is not on their end.


I would recommend starting a packet capture on the phone, then making a test inbound call.

If you don’t know how to read a packet capture, post it up here and one of us will help you understand it.

My initial thoughts are:

  1. Too long of a register expiration period (NAT port is closing)
  2. SIP ALG on the router is blocking something.
  3. Basically networking issues all around. Possibly even DNS.