All cells belonging to a particular virtual path are routed the same way through the ATM network and resulting in faster recovery in case of major failures. This class is used for emulating circuit switching. The cell rate is constant with time. CBR applications are quite sensitive to cell-delay variation. This class allows users to send traffic at a rate that varies with time depending on the availability of user information.
Statistical multiplexing is provided to make optimum use of network resources.
Although the standard does not require the cell transfer delay and cell-loss ratio to be guaranteed or minimized, it is desirable for switches to minimize delay and loss as much as possible. Depending upon the state of congestion in the network, the source is required to control its rate. The users are allowed to declare a minimum cell rate, which is guaranteed to the connection by the network. The following is the technical parameters to be associated with a connection. These terms are outlined in Table 2.