Asynchronous Transfer Mode (ATM) is an electronic digital data transmission technology designed for the high-speed transfer of video, voice and data through public and private networks. ATM is implemented as a network protocol and was first developed in the mid 1980s. ATM is an International Telecommunication Union Telecommunication Standardization Sector (ITU-T) standard and was jointly founded by Cisco Systems, NET/ADAPTIVE, Northern Telecom, and Sprint in 1991.
ATM has the following features:
- Fixed-size cells: permitting more efficient switching in hardware than is possible with variable-length packets
- Asynchronous multiplexing: permitting efficient use of interleaving and bandwidth of data of varying priority and size
- Connection-oriented service: permitting routing of cells through the ATM network over virtual connections, sometimes called virtual circuits.
There are three types of ATM services:
- Permanent virtual connection (PVC) service: connection between the points is direct and permanent. Therefore, PVC is similar to a leased line.
- Connectionless service: just similar to Switched Multimegabit Data Service (SMDS)
- Switched virtual connection (SVC) service: connection is created and released dynamically. As the connection stays up only as long as it is in use an SVC is similar to a telephone call.
ATM works on the reliability of digital lines to ensure data integrity and does not use error-correction protocols. Number of transmissions can take place at once, enabling ATM to accommodate multiple dialogues easily, quickly and reliably. It operates on a cell-based fast-packet communication method that supports transfer rates from 1.544 Mbps to 10 Gbps.
ATM can be installed into an existing network without upgrading the entire LAN!
So, we hope now you have an idea about ATM and its services.
