Delay analysis for CBR traffic in static-priority scheduling: Single-node and homogeneous CBR traffic case

The quality of the real-time traffic severely depends on its loss rate and delay time. In the integrated service networks, the real-time traffic and the non-real-time traffic share the network resources so that one can affect the quality of another and vice versa. In this context, it is very crucial to develop some mechanism to guarantee the quality-of-service (QoS) required by the real-time traffic. In this paper, we analyze the delay time of CBR packets from real-time sources when CBR packets have the priority over UBR packets in a manner that UBR packets are serviced only if no CBR packets are waiting in the buffer. Furthermore, we obtain various numerical results on the statistical bound on delay time such as the 99.9-percentail delay and compare it with the deterministic bound. By the comparison, we show that CAC (Call Admission Control) based upon the statistical bound is very effective in using the network resources efficiently when CBR packets can tolerate some loss due to late arrival.