[Serusers] Multiple cisco ATAs behind NAT - One way audio

[Jiri Kuthan]

At 09:06 PM 12/21/2003, Chris Mulhern wrote:
>I was wondering if anyone can help me.  We  (my company) are having a problem with sending calls to multiple Cisco ATA 186s behind a NAT.  We get one way audio.....we have a company in Iraq that is part business, but also a relief organization.  We need someone to help us get these calls working, so that a doctor from Boston can call into a hospital in Baghdad and work with the doctors there (for example).  We have VoIP and networking people working on it, but there is a problem with the port assignments (not sure of more detail yet). 

Well, ATAs don't have very good NAT traversal properties -- modern
phones support STUN. Since there are NATs which are hard-to-traverse
even for STUN-capable phones, you also need to solve such cases
on the SER part. Getting over NATs is generaly a tricky manner for
which you need a solid strategy. Let me know if you still need help
on this.

-jiri