I have vonage. It's been installed for about 6 months. I can't help
you on the shaing rules, but I will give you this add'l information.

The Linksys VOIP router they sent me was crap. (RP31P2). In terms of
working as a router/firewall, I had no complaints. I had m0n0wall
sitting behind it and never saw any firewall rules entries in the the
log.

As for VOIP, the RP31P2 Qos was terrible. Dropped calls, re-verb,
crackle, ...on-n-on. The Qos was worse than a cell phone...honest. I
was on the phone with vonage 7 times with 7 different tech's each
swearing nothing was wrong with my hardware. Oddly enough, even the
dslreports tools sort-of confirmed this.

As a last resort, I borrowed a friends Motorola VT1005. The difference
was night-n-day. Called Vonage back and told them to either send me a
new device or cancel my plan.

Got the new device !

My home LAN is setup like this

---inet---VT1005---m0n0---LAN

Putting the VT1005 ahead of m0n0wall eliminates the need to introduce
shaping. Shaping is done automatically by VT1005.

Regards,

Don