Asynchronous Transfer Mode (ATM) Switching

The Asynchronous Transfer mode or more popularly known as ATM is actually a part of the International Telecom Standards. Using the ATM protocols information can be sent and received in small secure cells. However for ATM connections to work there should be a constant connection. The ATM technology has found a large usage in cell switching and technologies that use multi-plexing. Also the benefits of using ATM technologies are that you can have a fixed bandwidth from 1 MBPS to Gigabytes.

ATM Devices Functionality

There are two components in an ATM device, one is the ATM switch and the other is the ATM end points. The ATM switch takes care of transmitting the cell through the network and the ATM end point receives the cell that has been transmitted by the ATM switch. The ATM endpoint is in turn connected to an interface adapter like routers and servers which convert the signals that have been received through cells into information that makes sense. The functionality is so easy and secure that financial institutions like banks prefer to use the ATM as secure transaction device to transfer money and make money accessible to its customers. ATM technology has made people’s lives easy to a large extent and is clearly demonstrated using the example of banks.

The cell that is being used to transfer information is a bit complicated in structure. Each cell is made up of 53 bytes and within it contains the header information or the source information and the user information. The cells are always streamlined by the network and they are not jumbled.

ATM Networks

The ATM technology basically combines circuit switching and the multiplexing technology with the packet switching. A combination of all these three networks has resulted in a fast and efficient way of transferring data. The bandwidth in ATM networks can be measured and customized to the needs. This bandwidth will be dedicated to the amount of data transfer you expect to do. There are technologies which follow the synchronous methods like the “Time Division Multiplexing”; however these technologies are not as effective as the Asynchronous technology. In ATM the time slots are readily available for the users and anyone can download information at any time.

In the ATM technology the ATM switches are connected from point to point. The benefit is there are no other points in the middle that the data has to travel through. They are directly read and interpreted by the receiving end which is connected to an interface. There are different kinds of interfaces that are used by the ATM’s to translate data. Like for example the UNI or the User to Network Interface and the NNI or Network to Network Interface. The UNI is used to connect the ATM switches to different interfaces, routers and servers. The NNI connects the two switches of the ATM.

The UNI and the NNI are further classified into public and private categories. The public categories have more security options since the ATM technology will be used for public access. The private UNI and the NNI can be customized to the level of security the company demands. In a public UNI and NNI network the switches are connected using the Broadband Intercarrier Interface depending on the distance between both the switches.

Standards supported by ATM
User to Interface Network
UNI versions 3.0, 3.1 and 4.0
Public Network Node Interface
Local Area Network Emulation
Multi-protocol on ATM’s
ATM is categorized as a high speed

ATM Switching Conclusion

ATM has proved itself an effective tool which can be customized for various networks and also has supported the view point that asynchronous models are much better than any other data transfer models available today.