If the CircuitType is Bilingual for a circuit, the router would use a Phase_IV compliant locally administered MAC address for that circuit and would be configured to communicate with Phase_IV and Phase_IV-Prime nodes over that circuit. A bilingual router can help communication between the Phase_IV and the Phase_IV-Prime nodes over the same extended LAN segment, and prevents a partitioned network. If the CircuitType is AMA ( Arbitrary MAC Address ) for a circuit, the router would use an arbitrary MAC address for that circuit, and would be configured to communicate with Phase_IV-Prime nodes over that circuit. If the CircuitType is PhaseIV for a circuit, the router would use the Phase_IV compliant locally administered MAC address for that circuit, and would be configured to communicate with Phase_IV nodes over that circuit.