[Asterisk-Users] Maximum retries exceeded w/SIP

[Brad Waite]

First of all, I'd like to send a big "thank you" to all the folks who have 
helped me get this far.

Now on to the next problem.  Here's my current network setup:


The Big I ---+--- FreeBSD FW --- * (10.0.0.253) ---- PC (10.0.0.1)
              |
              +--- Laptop (public IP)

natd is set up with the following rules:

redirect_port udp 10.0.0.253:10000-20000 10000-20000
redirect_port udp 10.0.0.253:5060 5060

* is set up with the demo/sandbox config.

I'm using XLite as my SIP client and have configured it on PC to work with *. 
I'm able to do everything I've tried so far.  I should, though - I'm on the inside.

However, when trying to make a call from the outside (via Laptop), something's 
breaking.  I've set up the SIP proxy in XLite to be the external interface on 
the firewall, and am able to log into the proxy without difficulty.  And while I 
can begin conversations, I can't keep them going for long.

For instance, when trying to call 500 at 10.0.0.253 (or 500 at FWpublicIP), I get most 
of the "demo-abouttotry" message - "I am about to attempt an IAX connection to a 
demonstration server located at Di" - at which point it gets cut off.  The 
console spits out the following error:

File chan_sip.c, Line 443 (retrans_pkt): Maximum retries exceeded on call 
FB9CEC48-7CE1-4171-895B-2DF048ED5D1F at 12.252.156.250 for seqno 12384 (Response)


Any ideas what could be going on?  My first guess is the firewall, but I can't 
figure out why some of the packets would get through while others apparently are 
not.  I'm at a loss.

Brad Waite
aka HankPoacher