[Kernel 2.6.26][rtp/rtcp]

Hello there,

I am currently working on a linux kernel 2.6.26 box with linked to multiple ISP (so one or more ethernet connections) and specific ones for VoIP usage.
What i want is to restrict SIP rtp/rtcp to specific interfaces (load-balance) and I can only use iptables rules kernel modules or hack the kernel itself (for resource purposes). My problem is that I have two different servers for sip rtp (port 5060) and sip rtcp (random port 10k+).
So when the rtcp connection is established, it is not related/expected to the rtp and I can't track it with iptables. (callback ip_nat_sip_expected in net/ipv4/netfilter/nf_nat_sip.c is not called).

box ----- > rtp server xxx.xxx.xxx.1

       \-----> rtcp server xxx.xxx.xxx.2

I am doing it wrong ?
Is there a kernel module that I missed ?
is this kind of trivia is dealt differently with more recent kernels ? (maybe i can convince my boss to upgrade).

Regards.

(French IT dev here, so sorry if english is a bit awkward).

Alexandre Moore
http://alexandremoore.com