TRAFFIC CONTROL IN TELEPHONY WITH ATMN STANDARDS

Abstract

The need to control traffic in telephony with Asynchronous Transfer Mode Network (ATMN) standards for multimedia traffic will greatly influence the design of future high-speed networks. Asynchronous Transfer Mode (ATM) is the transport method for carrying multimedia services, as proposed by CCITT. We consider the problem of traffic control in high speed networks for telephoney with ATMN standards. In broadband network, the high speed of the communication links and the varied nature of the carried traffic make such schemes inappropriate. Therefore simpler and more efficient schemes have to be proposed to fully exploit the large availablebandwidth. These schemes usually operate through input rate regulation. They force the information sources to limit their average input rate below some predefined rate while still allowing for a certain degree of burstiness. This ensures that no source will exceed for an extensive period of time the rate provided by the network during the call-setup procedure. The "Leaky bucket" scheme is an example of an input rate regulation. This kind of control will be provided for by introducing a "policing" or "usage parameters control" function. In this thesis two policing techniques, i.e. Leaky Bucket Method and LMT method are discussed. The performance of these methods is discussed and compared using computer simulation for packetised voice (telephoney) with ATMN standards as input traffic patterns. Performance is compared by computing cell loss probability (CLP) and delay.