[Serusers] Error 483 response to ACK and BYE

[SIP]

SIP wrote:
> In response to a BYE and an ACK from some (not all) servers that send to 
> our proxy, our server's spitting back a 483 'Too many hops' reply.
>
> It doesn't happen with all peers, and it certainly doesn't happen 
> locally...  but it does happen with some, and I'm not entirely sure as 
> to why.
>
> The 483 block at the beginning is normal:
>
>
> if (msg:len >  max_len ) {
>        sl_send_reply("513", "Message too big");
>        break;
> };
>
>
>
> Exchange looks like this:
>
> U 198.65.166.131:5060 -> 63.64.65.66:5060
> BYE sip:1101XXXXXXX at 63.64.65.66:5060 SIP/2.0.
> Record-Route: <sip:198.65.166.131;ftag=gpp0q468oh;lr>.
> Via: SIP/2.0/UDP 198.65.166.131;branch=z9hG4bK9b05.b75fbe14.0.
> Via: SIP/2.0/UDP 
> 192.168.1.51:2054;received=63.XX.XX.XX;branch=z9hG4bK-wdtud2nffq88;rport=2054.
> Route: <sip:63.64.65.66;ftag=gpp0q468oh;lr=on>.
> From: "User One" <sip:1747XXXXXXX at their.proxy.server:5060>;tag=gpp0q468oh.
> To: <sip:1101XXXXXXX at their.proxy.server;user=phone>;tag=as7fbbcb66.
> Call-ID: 3c267038e7ef-586eg1emcfsi at snom190.
> CSeq: 2 BYE.
> Max-Forwards: 16.
> Contact: <sip:1747XXXXXXX at 192.168.1.51:2054;line=oxd9zlst;nat=yes>.
> User-Agent: snom190/3.60x.
> Content-Length: 0.
> RemoteIP: 63.XX.XX.XX.
> P-hint: rr-enforced.
> P-NATed-URI: YES (1).
> P-RTP-Proxy: YES (1).
>
>
> U 63.64.65.66:5060 -> 198.65.166.131:5060
> SIP/2.0 483 Too Many Hops.
> Via: SIP/2.0/UDP 198.65.166.131;branch=z9hG4bK9b05.b75fbe14.0.
> Via: SIP/2.0/UDP 
> 192.168.1.51:2054;received=63.XX.XX.XX;branch=z9hG4bK-wdtud2nffq88;rport=2054.
> From: "User One" <sip:1747XXXXXXX at their.proxy.server:5060>;tag=gpp0q468oh.
> To: <sip:1101XXXXXXX at their.proxy.server;user=phone>;tag=as7fbbcb66.
> Call-ID: 3c267038e7ef-586eg1emcfsi at snom190.
> CSeq: 2 BYE.
> Server: Sip EXpress router (0.9.6 (i386/linux)).
> Content-Length: 0.
> Warning: 392 63.64.65.66:5060 "Noisy feedback tells:  pid=3488 
> req_src_ip=63.64.65.66 req_src_port=5060 
> in_uri=sip:1101XXXXXXX at 63.64.65.66:5060 
> out_uri=sip:1101XXXXXXX at 63.64.65.66:5060 via_cnt==18".
>
>
>
> What would be causing this? Is it because the IP address is being used 
> in the URI to us as opposed to the domain (I tried adding the IP to the 
> domain table and to an alias line alternately, but it didn't fix things) ?
>
> It's irksome in that it only happens with certain peers and not others, 
> so there's something in the way we're handling messages from them that's 
> not right or different, but since we handle all incoming the same way, 
> I'm at a loss as to why it works with some but not with others.
>
> N.
> _______________________________________________
> Serusers mailing list
> Serusers at lists.iptel.org
> http://lists.iptel.org/mailman/listinfo/serusers
>   
Obviously, that 483 block should have been:

if (!mf_process_maxfwd_header("10")) {
        sl_send_reply("483","Too Many Hops");
        break;
    };

And NOT the next block in the config. :)

N.