Asynchronous Transfer Mode (ATM)

Asynchronous Transfer Mode is a Wide Area Networking technology designed to offer high-speed connectivity and QoS features. In an ATM environment, information (voice, data, Internet and video) are transferred across the network in 53-byte segments known as cells. The fixed length of the cell allows ATM to transfer data more efficiently than either Frame Relay or Internet Protocol while delivering the highest degree of data integrity and extremely low latency.

The five-byte header incorporated in the ATM cell allows for addressing and QoS information to be tagged and switched (versus routed) without delay and per the priority assigned to the cell. SLA’s provided for ATM service are suitable for the most demanding customer and application.

ATM can be provided in a variety of access speeds which typically range from DS-1 to OC-12. ATM also lends itself to seamless interconnection with Frame Relay networks if a hybrid structure is desired.

From a process flow standpoint, CPE equipment sends the data from the local area network across a single physical access link connecting the customer facilities to the ATM port. The information is then transmitted across permanent virtual circuits (PVC’s) to the desired destination. Multiple PVC’s can/are provisioned across a single access link. Customers can select from multiple classes of service priority (CBR, VBR, ABR, UBR) to ensure that the application is delivered without latency or jitter.