X.25
Sign in to saveX.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). 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.
Key facts
- Technology standard.title
- X.25
- Technology standard.long_name
- 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
- Technology standard.image
- X25-network-diagram-0a.svg
- Technology standard.status
- In force
- Technology standard.year_started
- 1976
- Technology standard.version
- (10/96)
- Technology standard.version_date
- October 1996
- Technology standard.organization
- ITU-T
- Technology standard.committee
- Study Group VII
- Technology standard.domain
- networking
- Technology standard.website
- https://www.itu.int/rec/T-REC-X.25/
via Wikipedia infobox
Article
18 sectionsContents
- History
- How the CCITT standardized virtual circuits
- Worldwide public data networks
- Architecture
- Relation to the OSI Reference Model
- User device support
- Error control
- Addressing and virtual circuits
- Billing
- X.25 packet types
- X.25 details
- X.25 facilities
- X.25 protocol versions
- Legacy
- See also
- References
- Further reading
- External links
X.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). 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.
The protocol suite is designed as three conceptual layers, which correspond closely to the lower three layers of the seven-layer OSI Reference Model, although it was developed several years before the OSI model (1984). It also supports functionality not found in the OSI network layer. 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.