Topic summary
AAL5
Extracted from the Wikipedia article ATM Adaptation Layer 5.
Datagram encapsulation and IP MTU size
Internet Protocol (IP) can use AAL5, combined with one of the encapsulation schemes described in RFC 2684, to transfer datagrams across an ATM network, as specified in RFC 2225. Before data can be sent, a virtual circuit (PVC or SVC) must be in place to the destination host and both ends must agree to use AAL5 on the circuit. To transfer a datagram, the sender passes it to AAL5 along with the VPI/VCI identifying the circuit. AAL5 generates a trailer, divides the datagram into cells, and transfers the cells across the network. At the receiving end, AAL5 reassembles the cells, checks the CRC to verify that no bits were lost or corrupted, extracts the datagram, and passes it to the IP layer.