A method for transferring subscriber location information in a network communication system, including: converting the accessed subscriber location information into a code in the encoding format of the corresponding field in a subscriber packet to be sent outwards by the subscriber, carrying the code in the subscriber packet, and transferring the packet in the network communication system. It is also provided a method for converting MAC address, including: a network access device generating an MAC address from an MAC address resource pool; and replacing the source MAC address in a packet from a subscriber with said generated MAC address. The methods are no longer restricted by the number of permitted VLAN IDs in the network, and thereby improve feasibility of subscriber location information acquisition, providing a convenience for network operators to implement relevant extended services in network communication systems.