T.120

T.120 is a suite of point-to-multipoint communication protocols for teleconferencing, videoconferencing, and computer-supported collaboration.[1] It provides for application sharing, online chat, file sharing, and other functions. The protocols are standardised by the ITU Telecommunication Standardization Sector (ITU-T).[1]

T.120 has been implemented in various real-time collaboration programmes, including WebEx and NetMeeting.[2][3] IBM Sametime switched from the T.120 protocols to HTTP(S) in version 8.5.[4]

The prefix T designates the ITU subcommittee that developed the standard, but it is not an abbreviation. The ITU (re)assigns these prefixes to committees incrementally and in alphabetic order.[5]

The T.123 standard specifies that T.120 protocols use network port 1503 when communicating over TCP/IP.[5]

  1. ^ a b Clark, W. J. (1994). "Protocols for Multimedia Conferencing: An Introduction to the ITU-T T.120 series". In Hutchison, D.; Danthine, A.; Leopold, H.; Coulson, G. (eds.). Proceedings of the International COST 237 Workshop on Multimedia Transport and Teleservices. Springer-Verlag. p. 322. doi:10.1007/3-540-58759-4_43.
  2. ^ "Evaluation of Shared Display in WebEx and VNC". Community Grids Heritage Web Server: Summer 2000–2001. Indiana University Bloomington. Section: "Network communication". Retrieved 13 March 2018.
  3. ^ United States patent 6317777B1, Rune A. Skarbo; Christopher C. Lawless & Puneet Kukkal et al., "Method for web based storage and retrieval of documents", issued 2001-11-13, assigned to Intel 
  4. ^ Chiabra, Roberto. "What's New in Sametime 8.5" (PDF). IBM DeveloperWorks. IBM. Retrieved 13 March 2018.
  5. ^ a b Zwicky, Elizabeth D.; Cooper, Simon; Chapman, D. Brent (June 2000). "Multimedia Protocols". Building Internet Firewalls (2nd ed.). O'Reilly Media. Subsection: "Packet filtering characteristics of T.120". ISBN 978-1-56592-871-8. OCLC 639935671. Retrieved 20 February 2018.