[Asterisk-Users] Relative Newbie with a SIP/NAT issue

[Marty Mastera]

Hello,

Please forgive me if this has been addressed previously.  I have been
searching the archives and have not come across what I thought was a
solution.

My * server is behind a DSL router using a NAT IP address of 10.0.0.9. 
A colleague running XP and X-Lite can register with * from his home,
specifying my public IP as the SIP proxy in X-Lite (however this is only
true if I have the NAT flag set true in sip.conf on my end, otherwise he
cannot register with *).  Having configured extensions.conf to ring his
soft-phone via extension 334, I can call in via PSTN to the X100P, enter
the proper extension, and ring his softphone.  He can hear me but I have
no way of knowing if I can hear him as he does not currently have a
microphone.

The problem:  I have a context setup to allow dialing a local call to
the PSTN via the X100P.  This context is inlcuded in 'default'. 
'default' is also listed in the appropriate spot in sip.conf.  When my
colleague dials 9, plus an appropriate local telephone number, * does
indeed dial out via the X100P, but terminates the call within 5 seconds
or so, regardless of whether or not the call is answered.  I have
verified that the call is taking place as he can ring a separate PSTN
line from his softphone via SIP over the X100P.

The error, just prior to the disconnect:

WARNING[40966]: File chan_sip.c, Line 408 (retrans_pkt): Maximum retries
exceeded on call BED9714C-B16B-4C4B-AD55-2FD1B1E51B77 at 192.168.1.2 for
 seqno 44 (Response)
    -- Hungup 'Zap/1-1'

I notice his inside IP is listed in this error message, leading me to
believe that this has something to do with NAT....

On my end, I have port forwarded the pollowing ports to the * box from
the router: 5060, 8000, 8001, 16384-16391.  We have done nothing in the
way of changes on his end - he is using DSL and based on the IP listed
in the error, I assume he is also NAT'ed.

Pardon for being a bit long winded, given my short experience with *, I
feel it important to elaborate so as not to misinform those who might
help me!!!

Thank you,

Marty