Supports Class C traffic in message mode, only. Such traffic is variable bit rate (VBR) traffic with no timing relationship between the source and the sink, and consists of only one interface data unit (IDU). AAL Type 5 also is known as Simple and Efficient AAL (SEAL), as some of the overhead has been stripped out of the Convergence Sublayer (CS). AAL 5 also supports Class X traffic, which is variable bit rate (VBR) and specifically either unspecified bit rate (UBR) or available bit rate (ABR), and is either connection-oriented or connectionless in nature. AAL 5 is used in support of a wide variety of data traffic, including LAN Emulation (LANE) and Internet Protocol (IP). See also ABR, ATM, Class C ATM traffic, Class X ATM traffic, connectionless, connection-oriented, CS, IDU, IP, LANE, message mode service, sink, source, UBR, and VBR.