Complete Protocol dictionary, glossary and reference

AAL: ATM Adaptation Layer

The ATM Adaptation Layer (AAL) relays ATM cells between the ATM Layer and higher layers. When relaying information received from the higher layers, it segments the data into ATM cells. When relaying information received from the ATM Layer, it must reassemble the payloads into a format the higher layers can understand. This operation, which is called Segmentation and Reassembly (SAR), is the main task of AAL. Different AALs (AAL0, AAL1, AAL2, AAL3/4 and AAL5) were defined in supporting different traffic or services expected to be used.

Standard Organization

ATM Forum and ITU-T

Related Document

ITU-T I.363