tailieunhanh - Mạng và viễn thông P34

Quality o Service (QOS) and f Network Performance ( N P ) The maintenance of good quality for any product or service (. its ‘fitness for purpose’ and its price) isofsupremeimportance to theconsumerandthereforerequiresutmostmanagement attention. However, although it easy enoughto test a tangible product destruction, measureis to ment of the quality of a service is more difficult. | Networks and Telecommunications Design and Operation Second Edition. Martin P. Clark Copyright 1991 1997 John Wiley Sons Ltd ISBNs 0-471-97346-7 Hardback 0-470-84158-3 Electronic 34 Quality of Service QOS and Network Performance NP The maintenance of good quality for any product or service . its fitness for purpose and its price is of supreme importance to the consumer and therefore requires utmost management attention. However although it is easy enough to test a tangible product to destruction measurement of the quality of a service is more difficult. In telecommunication the customer is left with nothing more tangible than his or her own perception of how well the communication went. On a datalink the errors that have had to be corrected automatically are barely appreciated while in conversation unobtrusive bursts of line noise may go unnoticed. This is not to say that loss of data throughput on a datalink caused by continual error correction is of no concern to the customer nor does it mean that noises which disturb conversation are acceptable. What we really mean is that in measuring service quality due regard must be paid to anything of importance that the customer perceives and remembers. Concentration on setting and meeting quality targets should be paramount in planning and administration. Insufficient attention to them is the road to customer dissatisfaction and loss of business. This chapter reviews some aspects of communications quality and the practices of management with examples of the commoner quality parameters and control measures used by the world s major operators. FRAMEWORK FOR PERFORMANCE MANAGEMENT Good management of whatever industry demands the use of simple structured and effective monitoring tools and control procedures to maintain the efficiency of the internal business processes and the quality of the output. When all is running smoothly a minimum of effect should be required. However to be able quickly to correct defects or .