Effect of ATM networks on the leaky bucket based characterization of IS-IP guaranteed service flows in an IP-ATM internetwork

This paper addresses the problem of determining the change in the leaky bucket (LB) based characterization of a guaranteed service flow as it traverses an ATM subnet in an IP-ATM internetwork. The LB-characterization of the flow changes at the ATM network boundaries since overhead is added/removed and delay is introduced due to the mapping between IP packets and ATM cells. We obtained analytical results on the change in the LB-characterization by analysing the effect of the ingress AAL5, egress AAL5, and ATM schedulers on the guaranteed service traffic. We verified our analytical results by simulation, using OPNET. Our main contribution is the determination of how the leaky bucket based characterization of a guaranteed service flow changes as it traverses an ATM subnet. These results are very important for resource allocation within the ATM subnet to support end-to-end guaranteed service sessions.