This object indicates the type of circuit ID.If the type is default,the circuit ID will be the VLAN ID, Module ID and Port Number. If the type is user-defined ,the circuit ID can be defined by writing to the swDHCPRelayOption82CircuitId object.If the type is vendor1, the circuit ID will be the VLAN ID, Slot ID, Port Number and System��s MAC address. If the type is vendor2, the circuit ID will be the Port Number.If the type is vendor3,the circuit ID will be configured in swDHCPRelayOption82PerPortCircuitIdTable If the type is vendor4, the circuit ID will be the System Name, Module ID, Port Number and Client VLAN ID. If the type is vendor5, the circuit ID will be the System Name, 'eth', Chassis ID, Slot ID, Port Number and Client VLAN ID. If the type is vendor6, the circuit ID will be the Port Name, VLAN ID, System Name, Slot ID, Sub Slot ID, Port Number.