In ITU-T standards for asynchronous transfer mode (ATM), a class of traffic supported by ATM Adaptation Layer 5 (AAL5). Class X traffic is variable bit rate (VBR) and specifically either unspecified bit rate (UBR) or available bit rate (ABR) in nature. Class X traffic can be characterized as either connection-oriented or connectionless traffic with no timing relationship between the source and the sink. Class X traffic examples include LAN Emulation (LANE) and Internet Protocol (IP). See also
AAL,
AAL5,
ABR,
ATM,
connectionless,
connection-oriented,
IP,
ITU-T,
LANE,
sink,
source,
UBR, and
VBR.