[Asterisk-Users] Creating a SIP gateway for use behind NAT

[Leif Madsen]

Leif Madsen wrote:

> Hi all,
> 
> Here is a graphical diagram of what I am trying to do:
> 
> <SIP> <---> <GW/NAT/*> <--IAX--> <*> <--TDM400P--> <Analog Phone>
> 
> So I have incoming SIP calls go to the * on the GW, which I then want to 
> forward over IAX to the second * box behind the NAT GW.  If I was to 
> place a call on the second * box, it should then forward to the * on the 
> NAT GW and place the call to the SIP destination.  Thus, this should 
> create a 2 way communication between the * box BEHIND the NAT GW, and 
> end point.
> 
> Now, the REASON I am doing this is because the TDM400P card I have is an 
> older version, and has a lot of noise on the GW box, but is eliminated 
> when using it in the box behind the GW.  I realize I can just get this 
> card replaced, but I am just using it on loan from the school, so until 
> January comes around, I can't send it back, so this is my work around 
> until then.
> 
> I have built the IAX registrations between the boxes, so they register 
> with each other.  What I am trying to figure out is how to use my 
> existing dial plan which worked on the gateway.  This is going to work 
> with FWD, so I should be able to receive calls on my 18924 number, and 
> the 55555 welcome line as well.
> 
> Couple of questions:
> 
> 1) Should the GW or the second * box register with FWD?
> 2) Am I basically going to be using a blank configuration on the GW box, 
> and having the second * box with all the fancy dial plan stuff, or the 
> other way around?
> 3) Am I looking at using the switch => command?  If so, an example would 
> be fantastic, I've looked around on the digum list with google, but 
> can't seem to find anything, perhaps I'm just using the wrong search words?
> 
> Also, does my logic seem to make sense?  Again, I would have just loved 
> to put the TDM400P card in the GW machine, but unfortunately the dd line 
> to make the CPU go to 100% just isn't very practical since I would like 
> to use it for more than just *.
> 
> If I can think if anything else, I will reply to this post.
> 

Hmmmmm, seems as if any sort of documentation or how to use switch is 
hard to find.  If you know of a link, either on this list, or some 
external website, it would be very much appreciated.

Thanks,
Leif Madsen.