#REGION X PROTOCOL SERIES#

The X.25 specification is part of the larger set of X-Series. These books were published every fourth year with different-colored covers.

#REGION X PROTOCOL SERIES#

Various updates and additions were worked into the standard, eventually recorded in the ITU series of technical books describing the telecommunication systems. A few minor changes, which complemented the proposed specification, were accommodated to enable Larry Roberts to join the agreement. In particular, the work of Rémi Després, contributed significantly to the standard. Participants in the design of X.25 included engineers from Canada, France, Japan, the UK, and the USA representing a mix of national PTTs (France, Japan, UK) and private operators (Canada, USA). The CCITT (later ITU-T) Study Group VII began developing a standard for packet-switched data communication in the mid-1970s based upon a number of emerging data network projects. Representatives of PTTs and private companies who championed the development of X.25-based networks and services in Europe, North America and Japan. X.25 was also available in niche applications such as Retronet that allow vintage computers to use the Internet. by the credit card payment industry) and is still used by aviation, purchasable from telecoms companies. However, most users have moved to Internet Protocol (IP) systems instead. An X.25 WAN consists of packet-switching exchange (PSE) nodes as the networking hardware, and leased lines, plain old telephone service connections, or ISDN connections as physical links. Networks using X.25 were popular during the late 1970s and 1980s with telecommunications companies and in financial transaction systems such as automated teller machines. It also supports functionality not found in the OSI network layer. The protocol suite is designed as three conceptual layers, which correspond closely to the lower three layers of the seven-layer OSI model. This makes it one of the oldest packet-switching communication protocols available it was developed several years before IPv4 (1981) and the OSI Reference Model (1984). It was originally defined by the International Telegraph and Telephone Consultative Committee (CCITT, now ITU-T) in a series of drafts and finalized in a publication known as The Orange Book in 1976. X.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). X.25 Interface between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for terminals operating in the packet mode and connected to public data networks by dedicated circuit

Standard protocol suite for packet switched wide area network (WAN) communication

Region x protocol