Short for Asynchronous Transfer Mode, a network technology based on transferring data in cells or packets of a fixed size. The cell used with ATM is relatively small compared to units used with older technologies. The small, constant cell size allows ATM equipment to transmit video, audio, and computer data over the same network, and assure that no single type of data hogs the line.
Some people think that ATM holds the answer to the Internet bandwidth problem, but others are skeptical. ATM creates a fixed channel, or route, between two points whenever data transfer begins. This differs from TCP/IP, in which messages are divided into packets and each packet can take a different route from source to destination. This difference makes it easier to track and bill data usage across an ATM network, but it makes it less adaptable to sudden surges in network traffic.
When purchasing ATM service, you generally have a choice of four different types of service:
constant bit rate (CBR): specifies a fixed bit rate so that data is sent in a steady stream. This is analogous to a leased line.
variable bit rate (VBR): provides a specified throughput capacity but data is not sent evenly. This is a popular choice for voice and videoconferencing data.
available bit rate (ABR): provides a guaranteed minimum capacity but allows data to be burstedat higher capacities when the network is free.
unspecified bit rate (UBR): does not guarantee any throughput levels. This is used for applications, such as file transfer, that can tolerate delays.
- ATM OAM Ping
The ATM OAM Ping feature sends an ATM Operation, Administration and Maintenance (OAM) packet to confirm the connectivity of a specific permanent virtual circuit (PVC). The status of the PVC is displayed when a response to the OAM packet is received. The ATM OAM Ping feature allows the network administrator to verify PVC integrity and […]
Short for Advanced Television Systems Committee, it is an international, non-profit organization developing voluntary standards for digital television. The ATSC member organizations represent the broadcast, broadcast equipment, motion picture, consumer electronics, computer, cable, satellite, and semiconductor industries.
The modern-day shape and layout of PC motherboards. It improves on the previous standard, the Baby AT form factor, by rotating the orientation of the board 90 degrees. This allows for a more efficient design, with disk drive cable connectors nearer to the drive bays and the CPU closer to the power supply and cooling […]
- AT Bus
The expansion bus on the IBM PC/AT and compatible computers. The bus is the collection of wires and electronic components that connect all device controllers and add-in cards. The controllers are the components that attach to peripheral devices. The bus, therefore, is the main highway for all data moving in and out of the computer. […]
- AT command set
Pronounced ay-tee command set, the de facto standard language for controlling modems. The AT command set was developed by Hayes and is recognized by virtually all personal computer modems.