While inspecting the config of our UC520 I see it makes extensive use of BVI interfaces and bridge-groups. I see that the 802.11 radio and VLAN1 interfaces are part of a bridge-group 1 with a BVI interface setup for them and that my Voice VLAN also has a bridge-group and BVI associated with it. What is the purpose of the bridge-group and BVI interfaces? Can the setup work with just "normal" interfaces and VLANs? What would happen if I rip out all the bridge stuff?