How ATM works? Role of ATM in Internetwork


How ATM Works?

Asynchronous Transfer Mode (ATM) is a telecommunications technology that originated in the late 1980s and early 1990s. ATM was designed to efficiently transmit both voice and data traffic, making it suitable for a wide range of applications including voice, video, and data communication.

Note: It's important to clarify that ATM stands for Asynchronous Transfer Mode, not Asynchronous Transmission Mode.


ATM is capable of extremely hight-speed routing. At the lowest, it runs at 25 megabits per seconds. At the fastest, it can run up to 622 megabits per second. In addition to its speed, ATM is more complex than either Ethernet or Token Ring. ATM can provide for simultaneous data, video and voice transmission. It can be used for WAN, LAN and MAN. It can reach speeds of up to 2.488 gigabits per seconds.

On an ATM network, every station is always transmitting. However, Most of the cells transmitted are empty cells that can be discarded at the switch . When a cell that is not empty, enters the switch, the addresh are read to determine where the cell will go next. The cell is the sent out in the next available slot, according to the type of cell it is.

ATM cells can be encapsulated in other protocols, including those of FDDI (Fiber Distributed Data Interface), SONET (Synchronous optical networking), etc.

Role of ATM in Internetworks:

ATM has emerged as one of the technologies for integrating LANs and WANs. ATM can support any traffic type in separate or mixed streams, delay-sensitive traffic, and non-delay-sensitive traffics. ATM can also scale form low to high speeds. It has been adopted by all the industry's equipment vendors, from LAN to PBX (Private Branch Exchange) With ATM, network designers can integrate LANs and WANs to support emerging applications with economy in the enterprise. Network designers are deploying ATM technology to migrate from TDM (Time Division Multiplexing) networks for the following reasons:

  • To increase WAN bandwidth
  • To improve performance
  • To reduce down-time

In summary, in the context of internetworks, ATM refers to a networking technology that was once considered for high-speed, quality-of-service-aware communication. However, its adoption has declined in favor of other technologies like Ethernet and IP/MPLS.

Category: Networking

on: 17 Oct 2019

on: 09 Nov 2022

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