[Users] nat-rtpproxy.cfg

[Mark Kent]

A few months ago I downloaded example config files, as a way to
learning openser, but I'm not 100% sure where I got them.

One of them has this header:

# $Id: nat-rtpproxy.cfg 9 2005-08-19 15:30:55Z 
   /CN=Greger V. Teigre/emailAddress=greger at onsip.org $

I just found (re-found?) at onsip.org->downloads->Getting Started,
a later version of nat-rtpproxy.cfg with this header:

# $Id: nat-rtpproxy.cfg 51 2006-01-31 13:28:04Z 
   /CN=Paul Hazlett/emailAddress=paul at onsip.org $

and they appear different only in the loose_route handling:

OLD:
   if (loose_route()) {
      if (has_totag() && (method=="INVITE" || method=="ACK")) {
         if (nat_uac_test("19")) {
            setflag(6);
            force_rport();
            fix_nated_contact();
         };
         force_rtp_proxy("l");
      };
      route(1);
      break;
   };

NEW:
   if (loose_route()) {
      if ((method=="INVITE" || method=="REFER") && !has_totag()) {
         sl_send_reply("403", "Forbidden");
         break;
      };

      if (method=="INVITE") {
         if (!proxy_authorize("","subscriber")) {
            proxy_challenge("","0");
            break;
         } else if (!check_from()) {
            sl_send_reply("403", "Use From=ID");
            break;
         };
         consume_credentials();

         if (nat_uac_test("19")) {
            setflag(6);
            force_rport();
            fix_nated_contact();
         };
         force_rtp_proxy("l");
      };
      route(1);
      break;
   };

Now, who wants to take a stab at explaining why this was changed?

Why was ACK checked for in the old version and not the new?
(my guess:  zero length message body messes with force_rtp_proxy)

Why does that INVITE logic appear in the new loose_route handler?
What case does that handle that the later "if (method == INVITE)"
doesn't handle?   Does this have something to do with re-INVITES?

For convenience, the two files are here:
 http://a.mainstreet.net/nat-rtpproxy.5.0.cfg
 http://a.mainstreet.net/nat-rtpproxy-2006.cfg 

And do we openser people have our own set of sample config
files somewhere on openser.org?

Thanks,
-mark