PER-STREAM JITTER ANALYSIS IN CBR ATM MULTIPLEXORS

Constant bit-rate (CBR) traffic is expected to be a major source of tr affic in high-speed networks. Such sources may have stringent delay an d loss requirements and, in many cases, they should be delivered exact ly as they were generated. A simple delay priority scheme will bound t he cell delay and jitter for CBR streams so that in the network switch es CBR traffic will only compete with other CBR traffic in the network s. In this paper we will consider a multiplexor in such an environment , We provide an exact analysis of the jitter process in the homogeneou s case. In this ease we obtain the complete characterization of the ji tter profess showing the inaccuracies of the existing results. Our res ults indicate that jitter variance is bounded and never exceeds the co nstant 2/3 slot. It is also shown that the per-stream successive cell interdepartures times are negatively correlated with the lag 1 correla tion of -1/2. Higher order correlation coefficients are shown to be ze ro. Simple asymptotic results on per-stream behavior are also provided when the number of CBR streams is considered large, In the heterogene ous case we bound the jitter distribution and moments. Simple results are provided for the computation of the bound on the jitter variance f or any mix of CBR streams in this case. It is shown that streams with a low rate (large period) do experience little jitter variance. Howeve r, the jitter variance for the high-rate streams could be quite substa ntial.