T.120
(Redirected from T.121)
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
[edit]| 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| T.136 | Remote device control application protocol | Superseded by H.281 | [18][19] |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] |
- ^ T.128 was previously called T.Share while in draft stage.
See also
[edit]References
[edit]- ^ 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.
- ^ "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.
- ^ 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
- ^ Chiabra, Roberto. "What's New in Sametime 8.5" (PDF). IBM DeveloperWorks. IBM. Retrieved 13 March 2018.
- ^ 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.
- ^ "T.120 : Data protocols for multimedia conferencing". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.121 : Generic application template". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.122 : Multipoint communication service - Service definition". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.123 : Network-specific data protocol stacks for multimedia conferencing". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.124 : Generic Conference Control". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.125 : Multipoint communication service protocol specification". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.126 : Multipoint still image and annotation protocol". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.127 : Multipoint binary file transfer protocol". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.128 : Multipoint application sharing". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ a b c d e f g Freedman, Alan. "T.120". Computer Desktop Encyclopedia. The Computer Language Company. Retrieved 3 March 2018.
- ^ "T.134 : Text chat application entity". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.135 : User-to-reservation system transactions within T.120 conferences". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.136 : Text chat application entity". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "H.281 : A far end camera control protocol for videoconferences using H.224". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.
- ^ "T.137 : Virtual meeting room management for multimedia conferencing audio-visual control". ITU.int. International Telecommunication Union. Retrieved 3 March 2018.