VoIP "Can't Hear Me, Can Hear Them" Issue

Symptom:

You have (deployed) a SIP VoIP telephone set (can also be a software SIP phone) at home. Your phone rings and you can even dial out but the recipient of a call cannot hear you, though you can hear the recipient's voice.

Issue:

This means that the SIP protocol is going though but the RTP protocol is not going through. This happens in a typical home WiFi "router" scenario connected to cable or DSL service.

Possible Fixes:

If you cannot make a call at all or if you cannot receive any calls at all: Check UDP 5060-5063 ports.

If the sound is an issue then try opening UDP Port 16384 - 16482, or 10000 - 20000. This depends on the phone implementation.


Note: If you are an Astound customer, try connecting the phone directly to the DMZ port provided by Astound.