I've been trying to prioritize some VOIP packets outgoing. Our ISP has specific specifications they will honor. I can use DSCP (26) or TOS (0x68, or 10). I have a Linksys WRT54GL running Tomato 1.28
In order to add these, I've logged in via SSH and I'm trying to use iptables to add a rule to the POSTROUTING chain. I first tried:
iptables -t mangle -A POSTROUTING -p udp --sport 5060 -j DSCP --set-dscp 26
The result is
"No chain/target/match by that name"
I then tried:
iptables -t mangle -A POSTROUTING -p udp --sport 5060 -j TOS --set-tos 0x10
Same result. I tried various other tos values, such as just '10' and I get:
iptables v1.3.7: Bad TOS value `10'
When I drop the DSCP/TOS specifications I can make a rule, but it doesn't help me since it doesn't have the needed spec. Example:
iptables -t mangle -A POSTROUTING --proto udp --sport 5060
This works, I can see a rule in the POSTROUTING chain, but it doesn't do anything.
What am I missing? What can I change to get TOS or DSCP into my rule?