The Research Of Network Service Performance Feed-back Control

QoS (Quality of Service) control technology is one of the most important technologies of the next generation network. In recent years, research in this field is a hot issue. QoS is the representation of some parameter for the quality about data transmitted in network. QoS reflect the ability of the computer network systems offer the network service. The object of QoS control is to offer the distinguish service assurance the performance of network and application services. The number of users and applications using Internet increases very quickly. Computer systems play a more and more important role in operation and management of the modern enterprise. Especially in a communication operation corporation, there are many computer network application systems. When system load exceeds a certain limit, the performance of the network server would drop sharply and the clients have to wait for a long time to get responses. The quality of service gets worse. Servers of information system overload and network congestion has become an increasing issue. The enterprise information systems are becoming more and more complex and providing many different types of businesses. How to allocate resources to various businesses in system is the key fact. This will be brought one of the important topics. It's also the significance of this thesis.In the begin of this thesis, the basic concept about computer network congestion control structure are introduced, and the research on source algorithm and link algorithm of end-to-end congestion control is summarized. There are two primary components in congestion control. One is the source algorithm executed by host computers and edge devices, the other is the link algorithm executed by network devices. Based on the interception, a passive network service performance feedback control methods are introduced. These congestion control methods through the use of feedback control systems, can do appropriate adjustment to the system to improve the quality of service. A computer simulation supports the validity of these stability criteria on this congestion control algorithm. It as the basis to achieve a network performance monitoring and feedback control system based Simple Network Management Protocol (SNMP). These systems have been used in the BOSS of a telecom operation company. And has been applied to improve the management of the enterprise information system.