Howto:VOIP through NAT routers

Abstract

This page discusses NAT traversal of VOIP.

Introduction

VOIP signaling involves the exchange of IP addresses. Signaling addresses and media addresses RTP or T.38).

If the signaling crosses network borders you may get in trouble with private IP addresses. If a inside endpoint hands-out a private IP address (signaling or media) the external endpoint woun't be able to reach that IP address.

What WILL work

The only leliable way to get the hole thing working is to handle the problem on the private network.

What you need

You need a Fullcone NAT router and a STUN server in the public network.