Data link switching: Present and future
P. W. Gayek · IBM Systems Journal · 1995
The integration of computer networks has made it increasingly important for networking equipment to simultaneously handle a variety of data communications protocols. Networking products known as routers have proven themselves capable of handling many multiprotocol networking requirements, but have had difficulty addressing some important network configurations. Two of the most widely implemented protocols, IBM's Systems Network Architecture (SNA) and Network Basic Input/Output System (NetBIOS™), have characteristics that make it difficult for routers to support them in the same way as routers support other protocols. Networking vendors have devised a number of methods for transporting SNA and NetBIOS data traffic, but these methods have been largely nonstandard and have had other disadvantages. Data link switching (DLSw), initially developed by IBM, has attracted considerable interest among router vendors as a standard way to handle SNA and NetBIOS traffic and avoid some of the problems of earlier methods. A multivendor interest group within an IBM-sponsored forum on Advanced Peer-to-Peer Networking™ has developed and recently issued a standard DLSw specification. This paper briefly compares DLSw to the technologies that preceded it, provides a tutorial of the Version 1 DLSw standard, and discusses possible directions in which DLSw may evolve.