T.120 is a suite of
point-to-multipoint
In telecommunications, point-to-multipoint communication (P2MP, PTMP or PMP) is communication which is accomplished via a distinct type of one-to-many connection, providing multiple paths from a single location to multiple locations.
Point-to ...
communication protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroniza ...
s for
teleconferencing,
videoconferencing
Videotelephony, also known as videoconferencing and video teleconferencing, is the two-way or multipoint reception and transmission of audio and video signals by people in different locations for real time communication.McGraw-Hill Concise Ency ...
, and
computer-supported collaboration
Computer-supported collaboration research focuses on technology that affects groups, organizations, communities and societies, e.g., voice mail and text chat. It grew from cooperative work study of supporting people's work activities and working ...
.
It provides for
application sharing,
online chat
Online chat may refer to any kind of communication over the Internet that offers a real-time transmission of text messages from sender to receiver. Chat messages are generally short in order to enable other participants to respond quickly. Ther ...
,
file sharing
File sharing is the practice of distributing or providing access to digital media, such as computer programs, multimedia (audio, images and video), documents or electronic books. Common methods of storage, transmission and dispersion include r ...
, and other functions. The protocols are standardised by the
ITU Telecommunication Standardization Sector (ITU-T).
T.120 has been implemented in various real-time collaboration programmes, including
WebEx and
NetMeeting
Microsoft NetMeeting is a discontinued VoIP and multi-point videoconferencing client included in many versions of Microsoft Windows (from Windows 95 OSR2 to Windows Vista). It uses the H.323 protocol for videoconferencing, and is interoperable w ...
.
switched from the T.120 protocols to
HTTP
The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide We ...
(
S) in version 8.5.
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.
The T.123 standard specifies that T.120 protocols use
network port
In computer networking, a port is a number assigned to uniquely identify a connection endpoint and to direct data to a specific service. At the software level, within an operating system, a port is a logical construct that identifies a specific ...
1503 when communicating over
TCP/IP
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...
.
Components
See also
References
External links
* {{official website, http://www.itu.int/rec/T-REC-T.120/en
ITU-T recommendations
ITU-T T Series Recommendations