Analysis of a rate-based traffic management mechanism for ABR service

The available bit rate (ABR) service class is defined in the ATM standards. Whether ATM networks can provide ABR service successfully depends on the traffic management mechanism that supports the service. This paper analyzes a closed-loop rate-based control mechanism for ABR service class. We derive expressions for the queue build ups in both transient and steady states, as function of the rate control parameters and feedback delay. We emphasize in the transient analysis the most stressful conditions that only occur in the ABR connections such as, initial transmission at peak cell rate and interactions with bandwidth guaranteed service classes (e.g., CBR). The analytical results presented can be used to estimate the buffer requirement for the switches to support the ABR service class. We show that the buffer requirement for the closed-loop rate-based control mechanism scales up with the feedback delay, the number of connections, and the initial rate of the source