A packet network interface apparatus includes a media access control (MAC) module for constructing a packet for transmission over a packet network and a physical coding sublayer (PCS) module for encoding the packet for transmission over a physical interface. An inter packet gap module located between the MAC module and the PCS module directly transfers data to the PCS module while maintaining a certain inter packet gap by deleting or inserting idle characters. The inter packet gap module has at least one memory module for temporary storage of packet data. The modules preferably operate in a common time domain.