Also, if the equipment bursts at the PCR for longer than the burst tolerance , then the user equipment must send at a lower rate for a period of time so that the network can carry ABR and UBR traffic. Maximum cell loss rate is known. The switch does not specify the maximum jitter or a burst tolerance. Maximum cell loss rate is known. UBR No flow control.
Applications keep on transmitting when network congestion occurs.
Once switch buffers overflow, network discards cells. The network offers no guarantee of whether or when the data will arrive at the destination. This method requires that both the source and destination implement this form of flow control. The source decides how to allocate its allowed bandwidth among its virtual circuits. All of the network's ATM switches can generate and respond to the RM cells.