This introduction to OSI fundamentals provides extensive coverage of the services and protocols at each layer, with an emphasis on the upper layers. Experts Jain and Agrawala offer a mix of fundamentals and theory for network managers and designers and all data communication professionals who need a complete, detailed understanding of OSI. The book discusses the OSI architecture and its various applications, including how to define the service provided by a given layer; specifying a protocol that realizes a given service; protocols for the physical layer through the network layer; the complex protocols used at the transport layer; the problem of information representation and its solution; commonly used application services; major issues concerning implementation of OSI-based networks; and much more.