Resource allocation for worst case traffic in ATM networks

This paper addresses the problem of resource allocation for ATM connections carrying either CBR or VBR applications, for the first generation of ATM equipments. Evaluating the resources needed for the transfer phase of an ATM connection is a first step in the design of a CAC taking into account both call and transfer level QoS. The required amount of resources is estimated on the basis of traffic characteristics negotiated at call set-up, under the assumption that the offered traffic is a purely periodic pattern of active and inactive periods; this assumption is currently considered to yield upper bounds for the amount of resources which must be allocated to a connection. The traffic characteristics, and the corresponding periodic patterns of traffic are obtained using the ITU-T specification of ATM traffic control. We identify three frameworks (allocation on the basis of PCR, burst loss and burst delay framework in case of statistical multiplexing) and principles on which resource allocation can be based in each of these frameworks are highlighted.