Asynchronous Transfer Mode
“Asynchronous Transfer Mode (ATM) is a new method of switching and transporting data across LANs and wide area networks (WANs). ATM is capable of moving voice, data, graphics and video images at speeds of up to 2 gigabits per second.” (InfoWorld) ATM is designed to provide fast packet switching over various types and speeds of media at different rates from 64 kbps to 2 Gbps and beyond. ATM can handle any kind of information (voice, data, image, text and video) in any blend manner. ATM provides good bandwidth flexibility and can be used efficiently from desktop computers to local area and wide area networks. ATM is a connection-oriented packet switching technique in which all packets are of fixed length (53 bytes -- 5 bytes for header and 48 bytes for information). This connection-oriented technology allows for the passing of multiple types of service traffic over the media, making ATM the grand network technology cover all service types available today. (iol.unh.edu) The beginnings of ATM were first developed by researchers at AT&T Bell Laboratories and France Telecom’s Research Center in the early to mid-1980. These researchers were interested in packetizing voice information so that one switching fabric could be used for both data and voice. Researchers believed that a device capable of packetizing and switching voice information would need to move at least one million packets per second with millisecond-range delays. Because no existing packet-switching technology was capable of these speeds, the researchers were forced to consider new standards. Until very large scale integration (VLSI) technology became established; the content of a message was transparent to the intelligence of a switch. Switch intelligence was applied only to call setup. Early ATM researchers realized that incorporating VLSI technology into a switching fabric enabled switches to examine and process the contents of a packet header and provide...
Please join StudyMode to read the full document