Introduction to ATM

ATM networks provide a unified communication infrastructure capable of carrying telecommunication, video communication, and data communication between users around the globe.

ATM network technology is characterized by cell switching. ATM is a standard form of cell switching based on 53-byte cells. Cell-switching networks provide the quality of both the current telephone networks, which use circuit switching, and the current data networks, which use packet switching.

ATM networks feature:

• Controlled communications delay (latency)

  Controlled communications delay, or latency, is inherent to ATM networks. This feature is due to the small cell size of 53 bytes, controller cell buffering, and high line speeds.

• Scalable over physical size, speed, and node count

  ATM networks can be scaled geographically. Because ATM networks can be scaled indefinitely, they tend to eliminate the distinction between LANs and WANs.

• Bandwidth on demand

  Data can be delivered at various rates, as desired. All LANs provide this capability now.

• Virtual circuit multiplexing

  Virtual circuit multiplexing allows many dialogs to occur simultaneously over a single physical interface. This provides greater flexibility and simplicity than traditional telephone networks because more than a single call can be placed on a single physical interface.