CHARACTERISTICS OF ATM CELL MULTIPLEXER USING PRIORITY SCHEMES

Abstract

CCITT and domestic standard forums have proposed asynchronous transfer mode (ATM) as the transport mukiplexintg technique across the user network interface of broadband ISDN. Traffic in ATM based broadband networks must be properly controlled to permit efficient use of network resources while it provides good quality of service (QOS) to all network users. However, the excessive use of bandwidth may cause traffic dependent deeterioration. such as cell delay and loss at the buffer. Hence, efficient management of bandwidth and traffic controls are required to meet regtasite QOS standards. Two QOS management methods are feasible: To define a single QOS class and manage the QOS of all the media information equitably or to define multiple QOS and manage eh different classified medium individually. Two multiple QOS ways are studied. First one requires a single buffer for all the QOS and the second requires independent buffer for each Q0S class. Over and above for a sire buffer queuing model, different scheduling and pushout schemes were analysed In this analysis various scheduling disciplines, such as, head of line (HOL) Shortest line first (SLF), Longest line first (LLF) were considered By dividing the total buffer spaces into two parts, a push out scheme was created that permitted control phase of buffer spaces between two classes. Independent buffer queuing model also known as priority assitnent control was analyzed for two types of traffic models i.e. random tragic model and burs r tragic model In this QOS control method a way for satisfying the cell delay uses larger queues so that any cell that might eventually exceed its delay bound is not discarded immediately but rather clipped at the output if it exceeds delay bound.