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]

Components

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Number Title Status Refs
T.120 Data protocols for multimedia conferencing In force [6]
T.121 Generic application template In force [7]
T.122 Multipoint communication service - Service definition In force [8]
T.123 Network-specific data protocol stacks for multimedia conferencing In force [9]
T.124 Generic Conference Control In force [10]
T.125 Multipoint communication service protocol specification In force [11]
T.126 Multipoint still image and annotation protocol In force [12]
T.127 Multipoint binary file transfer protocol In force [13]
T.128 Multipoint application sharing[a] In force [14][15]
T.130 Realtime architecture ? [15]
T.131 Network specific mappings ? [15]
T.132 Realtime link management ? [15]
T.133 Audio visual control services ? [15]
T.134 Text chat application entity In force [16]
T.135 User-to-reservation system transactions within T.120 conferences In force [17]
T.136 Remote device control application protocol Superseded by H.281 [18][19]
T.137 Virtual meeting room management for multimedia conferencing audio-visual control In force [20]
T.RES Reservation services ? [3][15]
T.TUD User reservation ? [3][15]
  1. ^ T.128 was previously called T.Share while in draft stage.

See also

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References

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  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. ^ a b c 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.
  6. ^ "T.120 : Data protocols for multimedia conferencing". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  7. ^ "T.121 : Generic application template". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  8. ^ "T.122 : Multipoint communication service - Service definition". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  9. ^ "T.123 : Network-specific data protocol stacks for multimedia conferencing". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  10. ^ "T.124 : Generic Conference Control". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  11. ^ "T.125 : Multipoint communication service protocol specification". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  12. ^ "T.126 : Multipoint still image and annotation protocol". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  13. ^ "T.127 : Multipoint binary file transfer protocol". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  14. ^ "T.128 : Multipoint application sharing". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  15. ^ a b c d e f g Freedman, Alan. "T.120". Computer Desktop Encyclopedia. The Computer Language Company. Retrieved 3 March 2018.
  16. ^ "T.134 : Text chat application entity". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  17. ^ "T.135 : User-to-reservation system transactions within T.120 conferences". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  18. ^ "T.136 : Text chat application entity". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  19. ^ "H.281 : A far end camera control protocol for videoconferences using H.224". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
  20. ^ "T.137 : Virtual meeting room management for multimedia conferencing audio-visual control". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
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