DATA LINK SWITCHING - PRESENT AND FUTURE

The integration of computer networks has made it increasingly importan t for networking equipment to simultaneously handle a variety of data communications protocols. Networking products known as routers have pr oven themselves capable of handling many multiprotocol networking requ irements, but have had difficulty addressing some important network co nfigurations. Two of the most widely implemented protocols, IBM's Syst ems Network Architecture (SNA) and Network Basic input/Output System ( NetBIOS(TM)), have characteristics that make it difficult for routers to support them in the same way as routers support other protocols. Ne tworking vendors have devised a number of methods for transporting SNA and NetBIOS data traffic, but these methods have been largely nonstan dard and have had other disadvantages. Data link switching (DLSw), ini tially developed by ISM, has attracted considerable interest among rou ter vendors as a standard way to handle SNA and NetBIOS traffic and av oid some of the problems of earlier methods. A multivendor interest gr oup within an IBM-sponsored forum on Advanced Peer-to-Peer Networking( TM) has developed and recently issued a standard DLSw specification. T his paper briefly compares DLSw to the technologies that preceded it, provides a tutorial of the Version 1 DLSw standard, and discusses poss ible directions in which DLSw may evolve.