Packet Queueing Delay in Resilient Packet Ring Network Nodes

The packet queueing delay is one of the most important performance measures of a data net-work and is also a significant factor to be considered in the scheduling buffer design for a network node. This paper presents a traffic queueing model for resilient packet ring (RPR) networks and a method for quantitatively analyzing queueing delays in RPR nodes. The method was used to calculate the average queueing delays of different priority traffic for different transit queue modes. The simulations show that, in the transmit direction, lower priority traffic is delayed more than higher priority traffic, and that Class-A traffic is delayed more in a single-queue ring than in a dual-queue ring. In the transit direction, the secondary tran-sit buffer in the dual-queue ring contributes more to the traffic delay than the primary transit buffer in the sin-gle-queue ring, which in turn causes more delay than the primary transit buffer in the dual-queue ring.