802.1QinQ Support

Is there any support, either inbuilt or third party, that anyone knows of
for 802.1QinQ, VLAN Stacking, Inner VLAN (it's called a lot of things by a
lot of companies)?

The reason I ask is that we provide layer 2 transit over our wireless
network using a freebsd 5.4 / 6 appliance.  Recently we have been approached
by a group that wants to use VLANS for QOS using their own routers but
unless we encapsulate their traffic in our own VLANs we will eventually run
into an issue with VLAN conflicts between this group and another potential
VLAN user.  Any input that the FreeBSD community has to offer on this issue,
or other solutions that we may not have thought about would be greatly
appreciated.

Regards
 
Tim Price
Software Supervisor
ThePacific.Net
tim_at_thepacific.net
+64 3 5439095
www.thepacific.net