[Asterisk-Users] Asterisk, IAX and NAT issue

[Simon J Mudd]

dtoma at fx.ro ("Dan") writes:

[snip]
> Now, on the other PBX I have the following in extensions.conf
> 
> exten => _1XX,1,Dial(IAX/pspbx at n.n.n.n/${EXTEN})
> exten => _1XX,2,Hangup
> exten => _1XX,102,Hangup
> 
> where n.n.n.n is the external IP address of the NAT router.
> pspbx is the IAX user defined on the PBX behind the router, in iax.conf file
> like that:
> 
> [pspbx]
> type=user
> username=pspbx
> auth=plaintext
> permit=0.0.0.0/0.0.0.0
> host=dynamic
> context=fullaccess
> ;allow=all
> 
> When I try to call extension 103, I get on the local PBX console (the one
> connected directly to the internet):
> 
>     -- Executing Dial("SIP/351-d7ca", "IAX/pspbx at n.n.n.n/103") in new stack
>     -- Calling using options
> 'exten=103;callerid="MyOffice"<351>;language=en;username=pspbx;formats=2;cap
> ability=65283;version=1;adsicpe=2'
>     -- Called pspbx at n.n.n.n/103
>   == No one is available to answer at this time
>     -- Hungup 'IAX[n.n.n.n:5036]/46'
>     -- Executing Hangup("SIP/351-d7ca", "") in new stack
>   == Spawn extension (fullaccess, 103, 2) exited non-zero on 'SIP/351-d7ca'
> 
> and a busy tone.
> Nothing one the console of the other PBX.
> 
> The PBX behind the NAT is in DMZ (so completely exposed to the internet).
> Making a VPN connection between the two PBX (using PPTP) it works in both
> direction, so this is only a NAT related issue.

Is your firewall redirecting incoming connections on n.n.n.n:5036 to
the Internal Asterisk instance?  If you don't see any messages on the
inside Asterisk box it's unlikely.

The best thing to do is probably do a tcpdump -n -i eth0 host n.n.n.n
and host x.y.z.u (or similar) and try and diagnose what is actually
being sent over the wire.

Simon