a plurality of input ports for receiving packets, the input ports including a first port to be coupled to an Internet Protocol (IP) network and a second port to be coupled to a Multi Protocol Label Switching (MPLS) network;

a plurality of output ports for transmitting packets, the output ports including a third port to be coupled to the IP network and a fourth port to be coupled to the MPLS network;

a routing information table having a plurality of table entries; and

a processing unit for performing a header converting process of an input packet in accordance with an output routing information of a specific layer in the Open Systems Interconnection (OSI) reference model determined upon receipting the packet, and for outputting the packet to one of said output ports specified by output port identification information determined upon receipting the packet,

wherein the table entries define a combination of routing information of a plurality of layers in the OSI reference model, and

wherein each of the output routing information of a specific layer in the OSI reference model and the output port identification information is determined in correspondence with the combination of routing information of a plurality of layers in the OSI reference model.