[Asterisk-Users] SER and NAT

[Sanford E. Walke IV]

I have a really simple question about a fairly complex problem:

I have a Cisco 7960 behind a NAT.  I have an Asterisk server behind
a different NAT.  I have a SER server (with rtpproxy installed) on a 
public IP adress.   I've opened ports with static NAT to * and the 
Cisco.  Without using SER, I can register the phone to *, I can complete 
calls, I just can't move audio.  Reading the archives and voipinfo 
seems to indicate that I can use SER and rtpproxy as a "middleman" for 
the two things I want to talk to each other.  The problem is that no one 
ever seems to mention the simplest part of that config: HOW?

How do I make the Cisco talk to the * server through the SER server?

Do I register the Cisco to the SER server, and do I rewrite the URIs to
forward everything to * ?  Then how do I talk back to the Cisco?

Do I set the SER server as a proxy server on the Cisco, but not register?  
Do I just wave a wand and magically everything works?  I've read the docs 
at iptel.org, but they don't seem to mention it either, or I'm just missing 
it, or they're using some language I don't understand.  

Why is such a basic thing not covered somewhere?  Is there some basic
piece of documentation I've just missed in the 4 days of searching for 
this that I've been doing?

Any help would be greatly appreciated.  Requests for my current configs 
will be laughed at, because that's not what I'm asking about, I'm asking
about the most basic of concepts, as far as *how this works*, not a specific
application/implementation problem.

Thanks.

-- 
Sandy 
Freedom is the opportunity to take responsibility for your actions.
I don't speak for anyone but myself, and sometimes not even that.