ARCHIVED: What is an X.25 network?

An X.25 network is an older packet-switched network based on Open System Interconnection (OSI) network architecture rather than on TCP/IP architecture. It is mostly used for commercial networks. It allows WAN-to-WAN or LAN connectivity at up to 2Mbps (megabits per second), but due to heavy error-checking protocols, its effective network speed is very slow. A newer network standard known as Frame Relay is derived from the X.25 networking standard.

The main virtue of the X.25 standard is that it is extremely reliable and has superior error-checking capabilities. It also allows for virtual circuits and easy accounting of line usage. This makes the X.25 standard a good choice for networks where a significant amount of "line noise" is in the data transmission media, such as bad phone connections or data transmission by shortwave radio. For example, networks that use the X.25 protocol are important in countries without a modern telecommunications infrastructure. Also, the protocols used in packet radio (e.g., AX.25) are derived from X.25.

More information on X.25 networking is available at:

  http://www3.rad.com/networks/infrastructure/packet/main.htm