An interface which enables a LAN connected workstation to concurrently communicate with a plurality of computer platforms having respective network architectures over the same physical connection. The interface receives data from a LAN connection, examines the data and identifies the format being used. Based on the identified format, the interface determines the appropriate destination for the data and sends the data to that destination. Additionally, the interface enables a workstation running XNS software to run terminal emulation programs at the increased speed available from a LAN connection by enhancing the XNS protocol with (1) message segmentation and reassembly, (2) maximum packet size negotiation and (3) LAN address discovery.