Research Of Network Congestion Control Based On The Utility Optimization

Accompanying with the rapid increase of Internet users, it will be more important to control congestion. However, the traditional TCP congestion control protocols based on end system have been unable to adapt to these changes. Utility and prices in microeconomics provide a new direction for congestion control. Price instruments are useful in achieving market balance conditions in various markets. They can be also used for control of composite network systems. Internet pricing is essential not only for better possible understand of the network operation but it may also provide means to achieve rational behavior of the network users. Dynamic pricing may be useful, in particular, for balancing demand for access to application servers and for proper valuation of different classes and qualities of service. Utility can measure the user’s satisfaction or happiness about the service they acquire. Network Utility Maximization (NUM) have caught the attention of many scholars, it involves various knowledge of the computer network, the mathematical optimization methods, control theory and economics. Congestion control involves with resource allocation, reasonable allocation of the network resources will control congestion. Utility maximization model optimizes allocation which involves efficiency and fairness, so it measures resource allocation more comprehensively.The main research direction for NUM is to change the utility function or increase the constraint conditions; this will produce a different pricing method, and then influence the congestion control algorithm. This paper introduces the general model of NUM and how to solve it:using gradient algorithm to calculate link prices, and analyses its basic performances. This paper consider utility involved link importance on tow points:First, proposing a new shortest path algorithm based on link importance, which combined with utility model, producing a new congestion method; Second, introducing a new utility model, which improves the original pricing method, introduce a link utilization change factor, together with the original link congestion prices to adjust the source rate.The objective in this paper has two sides:One is to present emerging, opportunities to use price mechanisms for management of computer networks. Another is to present opportunities to involve utility and the link importance, and the final contrast analysis shows the validity, in this method, the information which links feedback can not only make the source adjust rate, but also optimize routing.