Why Does a VoIP User Hear Echo Only on External Calls?

Echo that appears only on external calls may involve an endpoint, speakerphone, carrier path, gateway, or acoustic issue. The call route helps narrow the source.

What to check

Compare handset and headset calls, internal and external destinations, one-way versus both-way echo, and timestamps. Check recent codec or gateway changes.

Recommended next step

Isolate the route with controlled calls and adjust a single verified endpoint or network setting at a time. Informatix Systems can troubleshoot VoIP quality and call paths.