[Spce-user] Extrange SDP manipulation

[Andrew Pogrebennyk]

Hi,

On 09/05/2014 09:25 PM, Raúl Alexis Betancor Santana wrote:
>> > A small hint regarding the broken messages - you can capture the
>> > fragmented SIP messages with tcpdump using command like this:
>> > tcpdump -s0 -v port 5060 or '(ip[6:2] & 0x1fff) != 0'
> It's not a problem about fragmented packets, first because ONLY the
> packet of the reinvite it's truncated, and also I'm getting the trace
> with sngrep, so allways see the 'SIP package dump' ... no matter if in
> one or 2 segments.
> 
> How could be a fragmentation problem with packets geting out from
> kamailio-lb to the UAC, if the UAC sends bigger packets to the
> kamailio-lb without fragmenting them ... also, kamailio-lb, sends
> packets bigger that that SIP-reinvite to the same UAC ... it's only a
> problem that appears if T.38 it's involved, if I force the UAC to do
> not try to negotiate T.38 ... a much bigger SDP goes across
> kamailio-lb, kamailio-proxy, sems and asterisk without any problem.

A wild idea: let's try the following, edit your
/etc/ngcp-config/templates/etc/kamailio/proxy/proxy.cfg.customtt.tt2,
then find comment which says "# fix for T.38 to patton faxserver
gateway" and comment out the whole blocks, two like this in different
parts of the config file:
>         if(sdp_content() && ($avp(s:from_faxserver) == 1 || $avp(s:to_faxserver) == 1))
>         {
>                 # fix for T.38 to patton faxserver gateway, which chokes on upper-case
>                 xlog("L_INFO", "Rewriting T.38 'UDPTL' to 'udptl' - [% logres -%]\n");
>                 replace_body_all(" UDPTL ", " udptl ");
>         }

and one like this:
>                 if($avp(s:from_faxserver) == 1 || $avp(s:to_faxserver) == 1)
>                 {
>                         # fix for T.38 to patton faxserver gateway, which chokes on upper-case
>                         xlog("L_INFO", "Rewriting T.38 'UDPTL' to 'udptl' - [% logreq -%]\n");
>                         replace_body_all(" UDPTL ", " udptl ");
>                 }
Once you disable three blocks in total, please execute ngcpcfg apply and
try again.

Regards,
Andrew