- ITU-T standard describing an addressing scheme used in X.25 networks. X.121 addresses are sometimes called IDNs (International Data Numbers).
- ITU-T standard for serial communications over synchronous digital lines. The X.21 protocol is used primarily in Europe and Japan.
- ITU-T standard that defines the physical layer protocol for communication between DCE and DTE in an X.25 network. Virtually equivalent to EIA/TIA-232. See also EIA/TIA-232 and X.25.
- ITU-T standard that defines how connections between DTE and DCE are maintained for remote terminal access and computer communications in PDNs. X.25 specifies LAPB, a data link layer protocol, and PLP, a network layer protocol. Frame Relay has to some degree superseded X.25. See also Frame Relay, LAPB, and PLP.
X.25 Level 3
- See PLP.
- See PLP.
- ITU-T recommendation that defines the terminal-to-PAD interface in X.25 networks. See also PAD and X.25.
- ITU-T recommendation that defines the form for control information in the terminal-to-PAD interface used in X.25 networks. See also PAD and X.25.
- ITU-T recommendation that defines various PAD parameters used in X.25 networks. See also PAD and X.25.
- Number assigned to the ANSI Task Group of Accredited Standards Committee for their internal, working document describing FDDI.
- ITU-T recommendation specifying a standard for electronic mail transfer.
- ITU-T recommendation specifying a standard for distributed maintenance of files and directories.
- ITU-T specification that defines the signalling system between two PDNs. X.75 is essentially an NNI. See also NNI.
X Display Manager Control Protocol
- See XDMCP.
Xerox Network Systems
- See XNS.
- exchange identification. Request and response packets exchanged prior to a session between a router and a Token Ring host. If the parameters of the serial device contained in the XID packet do not match the configuration of the host, the session is dropped.
- See termid.
- X Display Manager Control Protocol. Protocol used to communicate between X terminals and workstations running UNIX.
- Xerox Network Systems. Protocol suite originally designed by PARC. Many PC networking companies, such as 3Com, Banyan, Novell, and UB Networks used or currently use a variation of XNS as their primary transport protocol.
- Protocol developed specifically to optimize support for X Windows over a serial communications link.
- Major public PSN in the United States operated by MCI. Formerly called TYMNET.
- Terminal that allows a user simultaneous access to several different applications and resources in a multivendor environment through implementation of X Windows. See also X Windows.
- Distributed, network-transparent, device-independent, multitasking windowing and graphics system originally developed by MIT for communication between X terminals and UNIX workstations. See also X terminal.