VoIP udp packets prioritisation

sqn · 01-20-2006, 08:20 AM

Hi all,

I have a Alcatel PABX with a VoIP module in it witch allows me to use VoIP from the branches located in the company VPN. I need to make some packet prioritization, because the IP phone is not working quite ok, because the traffic between the main company and branches is very high. So can I do this using IPTABLES?
I belive i have to use the mangle table, but i really do not know how... this is the only branch that does not have a router and I use a linux.

Thx in advanced

zmanea · 01-22-2006, 11:53 AM

Are you marking the VOIP packets with TOS or diff serv values?

sqn · 01-23-2006, 07:53 AM

currently i am not marking any pakets, because i don't know... i just need a way to identify the voip pakets so i can mark them

zmanea · 01-25-2006, 09:32 PM

Some IP PBXs and phones will mark their packets with a TOS and/or DiffServ value. You will need to mark the packets with Iptables if they are currently not marked, but this is only half the battle. You will also need to prioritize the traffic at your border router, the priorities are based on the TOS/Diffserv values in your packets. Take a look at wondershaper if the border router is a linux box.