TRAFFIC MANAGEMENT FOR FRAME RELAY OVER ATM

Abstract

Recent improvements in transmission and switching technologies are producing more reliable networks 'thus reducing the heavy protocol and flow control overheads. In the light of these fact Frame Relay (FR) networks are being specified. FR service over a common Asynchronous Transfer Mode (ATM) backbone network requires an FR to ATM interworking unit(IWU). The functionality of this IWU directly impacts the engineering of the over all network in terms of capacity required, Quality of Service (QoS) expected, and the interference among different types of services being offered on the same platform like Switched Multimegabit Data Service(SMDS), FR service, Cell Relay (CR) service. Traffic shaping is necessary at customer location's equipment, otherwise the issue of policing and bandwidth allocation becomes much more critical. In the present dissertation, the problem of FR traffic descriptor mapping, the issue of traffic policing in the frame mode and the cell mode for FR service over ATM backbone have been studied. In addition to this problem, the issues related to bandwidth allocation when services entering through different interfaces within the ATM network are studied. This dissertation also proposes some simple modification in cell mode, to improve the system performance considerably. Simulation studies are carried out to compare their .performance. Findings suggests that the performance is somewhat independent of mode in which traffic control schemes operate. But from a cost point of view it is more advantageous to use cell mode traffic policing.