[OpenSIPS-Users] Change in SDP/RTP routing with Opensips 1.4 and 1.6

[Chris Stone]

Henk,

On Wed, Feb 9, 2011 at 3:48 PM, Henk Hesselink <opensips-users at voipro.nl> wrote:
> First off, the ngrep trace doesn't seem to match the debug log, f.i.
> the From: tag is different.  You might also want to check out -Wbyline
> for ngrep, makes reading the output a lot easier.

They were different calls - same source and destination DIDs, but 2
different calls....

> But ignoring the tags, the debug log shows "DBG:core:forward_request:
> sending:" and then the exact original message (with an extra Via: of
> course).  So it seems to me OpenSIPS is sending out what you'd expect.
>
> So I believe the munging is happening after the packet leaves OpenSIPS
> and before it is sent out on the wire.  Run "lsmod | grep nat" and see
> if you have "nf_nat_sip" (I'm assuming it's a Linux box), or maybe some
> other module that might be doing this.

Well, checked that and found a bunch of stuff:

[root at mars ~]# lsmod | grep nat
ip_nat_tftp            34881  0
ip_nat_snmp_basic      43461  0
ip_nat_sip             37313  0
ip_nat_pptp            39237  0
ip_nat_irc             35777  0
ip_nat_h323            40769  0
ip_nat_ftp             36545  0
ip_nat_amanda          35393  0
ip_conntrack_tftp      37913  1 ip_nat_tftp
ip_conntrack_sip       41745  1 ip_nat_sip
ip_conntrack_pptp      45665  1 ip_nat_pptp
ip_conntrack_irc       40465  1 ip_nat_irc
ip_conntrack_h323      88193  1 ip_nat_h323
ip_conntrack_ftp       41361  1 ip_nat_ftp
ip_conntrack_amanda    38345  1 ip_nat_amanda
iptable_nat            40773  0
....

and Googling  on that, found a bunch of hits that talked about
ip_nat_sip and nf_nat_sip causing exactly the problem I am seeing.
Exciting! So, removed those modules (rmmod), disabled them in
shorewall, made sure that /etc/modprobe.conf would not reload them,
restarted opensips and did a test call. Same problem. Checked the
modules and found the sip ones not loaded:

[root at mars ~]# lsmod | grep nat
ip_nat_tftp            34881  0
ip_nat_snmp_basic      43461  0
ip_nat_pptp            39237  0
ip_nat_irc             35777  0
ip_nat_h323            40769  0
ip_nat_ftp             36545  0
ip_nat_amanda          35393  0
ip_conntrack_tftp      37913  1 ip_nat_tftp
ip_conntrack_pptp      45665  1 ip_nat_pptp
ip_conntrack_irc       40465  1 ip_nat_irc
ip_conntrack_h323      88193  1 ip_nat_h323
ip_conntrack_ftp       41361  1 ip_nat_ftp
ip_conntrack_amanda    38345  1 ip_nat_amanda
iptable_nat            40773  0
.....

So, made sure shorewall was disabled and rebooted the box. Now, none
of these modules are active:

[root at mars ~]# lsmod | grep nat
[root at mars ~]#

Test call still fails though in the same way. DARN! Thought you had
hit on it! But, SDP is still being routed incorrectly:

[root at mars ~]# tethereal -i eth0 -f 'udp'
Running as user "root" and group "root". This could be dangerous.
Capturing on eth0
  0.000000 208.94.157.10 -> 67.212.153.178 SIP/SDP Request: INVITE
sip:17204497101 at 67.212.153.178:5060;transport=udp, with session
description
  0.000709 67.212.153.178 -> 67.212.153.179 SIP/SDP Request: INVITE
sip:17204497101 at 67.212.153.178:5060;transport=udp, with session
description
  0.002113 67.212.153.179 -> 67.212.153.178 SIP Status: 100 Trying
  0.010449 67.212.153.178 -> 208.94.157.10 SIP Status: 100 Trying
  1.005118 67.212.153.179 -> 67.212.153.178 SIP Status: 180 Ringing
  1.005920 67.212.153.178 -> 208.94.157.10 SIP Status: 180 Ringing
  3.006377 67.212.153.179 -> 67.212.153.178 SIP/SDP Status: 200 OK,
with session description
  3.007123 67.212.153.178 -> 208.94.157.10 SIP/SDP Status: 200 OK,
with session description
  3.031546 208.94.157.10 -> 67.212.153.178 SIP Request: ACK
sip:17204497101 at 67.212.153.179:5060
  3.032332 67.212.153.178 -> 67.212.153.179 SIP Request: ACK
sip:17204497101 at 67.212.153.179:5060
  3.046018 67.212.153.179 -> 67.212.153.178 RTP PT=ITU-T G.711 PCMU,
SSRC=0x621B0940, Seq=3994, Time=160, Mark
  3.063905 67.212.153.179 -> 67.212.153.178 RTP PT=ITU-T G.711 PCMU,
SSRC=0x621B0940, Seq=3995, Time=320
  3.083848 67.212.153.179 -> 67.212.153.178 RTP PT=ITU-T G.711 PCMU,
SSRC=0x621B0940, Seq=3996, Time=480
  3.103845 67.212.153.179 -> 67.212.153.178 RTP PT=ITU-T G.711 PCMU,
SSRC=0x621B0940, Seq=3997, Time=640
  3.123839 67.212.153.179 -> 67.212.153.178 RTP PT=ITU-T G.711 PCMU,
SSRC=0x621B0940, Seq=3998, Time=800
  .....


Still digging and looking for the answer....



Thanks


Chris