Available bit rate (ABR)
A relatively new concept. Based on flow control from the network (employing Resource Management = RM cells). In ABR, we need to specify the following traffic parameters:
-  Peak Cell Rate (PCR)
-  Minimum Cell Rate (MCR)
MCR is a bound (0 < MCR < PCR) on the cell rate that the network should support. However, the cell rate of the source is allowed to vary between 0 … PCR.
Typical applications:
-  LAN emulation / LAN interconnection
-  File transfer (critical applications)