ATM adaptation layer protocol

摘要

The ATM adaptation layer (AAL), as defined in the International Telecommunications Union (ITU) 1990 recommendations, will enhance the services provided by the ATM layer to support the functions required by the next higher layer. The question of what that next higher layer is has been a matter of controversy from the beginning of the AAL study. AAL protocol specifications are key to the success of B-ISDN services. They must be developed in a timely fashion, in cooperation with other standardization bodies such as ISO and the ATM Forum.