[LARTC] Filtering RTP/SIP protocol (Voip)?

[Mohan Sundaram]

Salim S I wrote:
> SIP is pretty easy. Normally it uses 5060 port. But prioritizing this
> port traffic won't enhance the overall voice quality.
> RTP ports are decided dynamically during SIP handshake. To filter RTP
> protocol from packet pattern will delay the traffic. So using port
> number is easier way, BUT, you need to find out these ports from the SIP
> handshake messages.
> How to prioritize depends on your setup's capabilities.
> 
Correct. However, some conntrack modules are available for such dual 
port (negotiated data port) protocols like ftp. Need to see if one 
exists for SIP. If so, iptables can be used to mark SIP data connections 
and the mark can be used for traffic classification.

Search netfilter.org mailing lists please.

Mohan