Glossary

AAL

ATM Adaptation Layer. The AAL translates digital voice, image, video, and data signals into the ATM cell format, and vice versa. There are four AALs defined (AAL1, AAL2, AAL3/4, and AAL5) that provide different services and have been recommended by the CCITT. The services have three distinguishing attributes: whether or not they require the transfer of timing information between source and destination, whether a constant or variable bit rate is supported, and whether the service is connectionless or connection-oriented. For example, AAL5 supports connection-oriented variable bit rate data services.

ABAP

A programming language used with SAP R/3.