SCHEDULING AND ADMISSION CONTROL POLICIES - A CASE-STUDY FOR ATM

Scheduling mechanisms and admission policies play an important role in optimising resource allocation in networks offering integrated servic es. The scheduler mediates the low-level contention for service betwee n cells of different classes, while admission control regulates the ac ceptance or blocking of incoming traffic on a connection-by-connection basis. These two levels of control are of course closely related in t he sense that if too much traffic is allowed to enter the network by a n overly lax admission control policy, then no scheduler will be able to provide the requested Quality of Service (QoS) for all traffic clas ses. A functioning admission control is a prerequisite for any guarant ee of cell-level QoS while its merit is to guarantee QoS efficiently a nd fairly, We focus on an ATM switch to demonstrate these principles. (C) 1997 Elsevier Science B.V.