below is my network config.

# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.

vconfig add wan 621
vconfig add wan 822
ifconfig wan.621 up
ifconfig wan.822 up
ifconfig lan1 up
brctl addbr br-voip
brctl addif br-voip wan.822
brctl addif br-voip lan1
ifconfig br-voip up
exit 0