Re: RTP proxy module

[Patrick McHardy <kaber@trash.net>]

Tomas Mandys wrote:
> I'm engaged in SIP router development and now I need improve our current 
> application concerning RTP proxy. SIP call need at least 2 UDP streams 
> (RTP&RTCP) for each session. But problem is when one client is hidden behind 
> the NAT. In this case a RPT proxy is essential. All RTP traffic goes through 
> RTP proxy, in our case it was userspace application but because it need only 
> redirect incomming packets to specified address or learn remote ip/port it's 
> unnecessary copying rtp data between kernel and userspace. So I developed 
> iptables module callled ipt_RTPPROXY+libipt_RTPPROXY that can do it in 
> iptables, i.e. more efficiently. It's different case than connection tracking 
> and NAT. It's not trivial, there is learning and expiration logic.
> 
> I also developed userspace utils that can alloc, update, delete, list RTP 
> sessions in iptables (using libipt_RTPPROXY). This is actually example how to 
> encapsulate functionality in SIP router. 

How is this different from the SIP conntrack/NAT helper, which can deal
(well, not entirely yet) with clients behind NAT as well?

> The module is written as patch-o-matic-ng.
> Is it possible publish in netfilter.org CVS as (currently) experimental 
> module? What procedure must new modules pass to be accepted?

We currently only accept patches for patch-o-matic that we have an
interest in maintaining ourselves (in case the author disappears,
which happens regulary). The two other possibilities are external
patch-o-matic repositories and/or an account on people.netfilter.org
if you just need some webspace to publish it.