On the PCR policing of an arbitrary stream passing through a private ATM network before reaching the public UNI

摘要

Any Call Admission Control algorithms and any Network Dimensioning depend on the reliability of the chosen Usage Parameter control algorithm. The standardized ATM UPC algoirhtm is the GCRA. An ideal ATM PCR policer should guarantee a very low cell loss probability (10~-9) for the cells of a well-behaved user and police contract violation by the source as rigidly as possible. All this independently of the characteristics of the monitored stream and of the background traffic. When we started our investigations no acceptable GCRA parameters dimensioning had been presented and no alternative policing solution could claim to be more general and simpler than the GCRA. We already provided an analytic GCRA parameters dimensioning which transforms the GCRA into an ideal PCR policer, also in the case of online PCR renegotiation, and into an ideal ACR policer of ABR services. In this paper we generalize our results to the PCR policing of a GCRA (T_PCR;tau_0) complying stream passing through an ATM network before reaching the public UNI. The GCRA dimenisoning we present allows the policer to discard no cell of a well-behaved user and to rigidly police contract violation. Our results hold for any kind of background traffic.