There is provided a packet transport layer apparatus. The packet transport layer apparatus can receive frames having different formats via a single port by dividing a single physical port into a plurality of virtual ports according to each frame format, can increase the number of customer virtual local area networks (C-VLANs) and the number of service VLANs (S-VLANs) being usable at the same time by assigning a different component identifier (ID) to each frame format and using the component ID as a factor used in searching a filtering table, and can translate a frame format to be suited to a frame format allocated to a virtual output port.