The International Standards Organisation (ISO) set up a sub- committee in 1977 to examine the development of a non- manufacturer-specific set of communications protocols to cover the requirements to be implemented by all manufacturers, to provide the buyer of a system supporting these protocols with the ready ability to set up heterogeneous networks of computers. At the present time most manufacturers are committed to the development of software to implement ISO protocols for Open System Interconnection as each new "layer" is finalised. This book introduces the International Standards Organisation's seven-layer model for Open Systems Interconnection (OSI), specifically covering the lower four layers which provide the communications subsystem, the upper three layers being increasingly oriented towards applications. The first chapter gives a detailed description of the OSI layerings and their present state of development, subsequent chapters progressing to layer four, the tranport layer, where transport service and other transport protocols, now in widespread use, are examined. Further protocols, also residing at the fourth level but defined prior to the main International Standards Organisation's main work (used for connecting terminals to host computer systems), are also included.
Table of Contents
Introduction; The Physical Level; The Link Level; The Packet Level; The Transport Level; 'Triple X'.