ATM Forum
Encyclopedia
The ATM Forum was founded in 1991 to be the industry consortium to promote Asynchronous Transfer Mode
technology used in telecommunication
networks. It was a non-profit international organization. The ATM Forum created over 200 implementation agreements.
The Frame Relay Forum (promoting frame relay
) also started in 1991. The MPLS Forum (which supported Multiprotocol Label Switching
had begun in 2000. Those two merged in 2003 to become the MPLS and Frame Relay Alliance (MFA).
In 2005, the ATM Forum joined forces with the MFA to form the MFA Forum, which was re-named to be the IP/MPLS Forum.
In May 2009 the IP/MPLS Forum merged with the Broadband Forum
.
DS0
and DS1
/E1 Plesiochronous Digital Hierarchy
(PDH) signals into Asynchronous Transfer Mode
(ATM) cells. It also supported J2 and DS-3 signals. The service was built around the ATM Adaption Layer 1
specification from the ITU
. The 1.0 version was approved about 1995 and the 2.0 version was approved in January 1997..
Asynchronous Transfer Mode
Asynchronous Transfer Mode is a standard switching technique designed to unify telecommunication and computer networks. It uses asynchronous time-division multiplexing, and it encodes data into small, fixed-sized cells. This differs from approaches such as the Internet Protocol or Ethernet that...
technology used in telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
networks. It was a non-profit international organization. The ATM Forum created over 200 implementation agreements.
History
ATM technology stabilized with the "Anchorage Accord", which established the baseline of ATM implementations. While ATM did not live up to every expectation, it remained an important core network technology.The Frame Relay Forum (promoting frame relay
Frame relay
Frame Relay is a standardized wide area network technology that specifies the physical and logical link layers of digital telecommunications channels using a packet switching methodology...
) also started in 1991. The MPLS Forum (which supported Multiprotocol Label Switching
Multiprotocol Label Switching
Multiprotocol Label Switching is a mechanism in high-performance telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, avoiding complex lookups in a routing table. The labels identify virtual links between...
had begun in 2000. Those two merged in 2003 to become the MPLS and Frame Relay Alliance (MFA).
In 2005, the ATM Forum joined forces with the MFA to form the MFA Forum, which was re-named to be the IP/MPLS Forum.
In May 2009 the IP/MPLS Forum merged with the Broadband Forum
Broadband Forum
The Broadband Forum is a non-profit industry consortium dedicated to developing broadband network specifications. Members include telecommunications networking and service provider companies, broadband device and equipment vendors, consultants and independent testing labs...
.
Sampling of specifications
- ATM-MPLS Network Interworking
- Multi-Protocol Over ATM
- TM 4.1
- User-Network Interface
- B-ICI
- ANNI
- PNNI
- Frame-based ATM
- ILMI
- 622.08 Mbit/s physical layer
- Inverse ATM Mux
- Circuit Emulation Service
- ATM Security Framework
Circuit Emulation Service
A widely adopted specification to emerge from the ATM Forum was the Circuit Emulation Service specification (CES). This specification defined a method of creating a service out of mapping TDMTime-division multiplexing
Time-division multiplexing is a type of digital multiplexing in which two or more bit streams or signals are transferred apparently simultaneously as sub-channels in one communication channel, but are physically taking turns on the channel. The time domain is divided into several recurrent...
DS0
Digital Signal 0
Digital Signal 0 is a basic digital signaling rate of 64 kbit/s, corresponding to the capacity of one voice-frequency-equivalent channel...
and DS1
Digital Signal 1
Digital signal 1 is a T-carrier signaling scheme devised by Bell Labs. DS1 is a widely used standard in telecommunications in North America and Japan to transmit voice and data between devices. E1 is used in place of T1 outside North America, Japan, and South Korea...
/E1 Plesiochronous Digital Hierarchy
Plesiochronous Digital Hierarchy
The Plesiochronous Digital Hierarchy is a technology used in telecommunications networks to transport large quantities of data over digital transport equipment such as fibre optic and microwave radio systems...
(PDH) signals into Asynchronous Transfer Mode
Asynchronous Transfer Mode
Asynchronous Transfer Mode is a standard switching technique designed to unify telecommunication and computer networks. It uses asynchronous time-division multiplexing, and it encodes data into small, fixed-sized cells. This differs from approaches such as the Internet Protocol or Ethernet that...
(ATM) cells. It also supported J2 and DS-3 signals. The service was built around the ATM Adaption Layer 1
ATM Adaptation Layers
The use of Asynchronous Transfer Mode technology and services creates the need for an adaptation layer in order to support information transfer protocols, which are not based on ATM...
specification from the ITU
International Telecommunication Union
The International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...
. The 1.0 version was approved about 1995 and the 2.0 version was approved in January 1997..