Cdn Content Switching Technology

With the development of the network technology,Internet users are getting better access. But we need a high-performance,reliable vehicle for the appearance of bandwidth-intensive,rich multimedia content such as ecommerce transactions,stream media. CDN is the current solution scheme to advance the user access speed and guarantee the network security.CDN can be divided into three independent building blocks in addition to the network infrastructure:Content Routing,Content Delivery,and Performance Measurement. There are two different aspects to content routing. The first is the global routing;the second addresses the local routing (or content switching),which is the main topic of this paper. Two factors,which affect the performance of the content switching,is dispatching algorithm and routing mechanism.Chapter 1 introduces the concept and design principle of CDN,and presents the three building block of CDN.Chapter 2 presents the architectures of content switching,classifies and describes main current routing mechanisms and dispatching request algorithms to split the load among the server nodes,and analyses their performance character qualitatively.Chapter 3 implements the simulation of traditional dispatching algorithms (WRR,URL Hashing and LARD),and analyses their performance character based on the result of simulation.Chapter 4 implements the simulation of traditional routing mechanism (Packet-rewriting,TCP handoffand TCP splicing),and then compares their performance character based on the result of simulation.Chapter 5 establishes the universal content switching queuing model,and calculates switching system theoretical performance.Last section concludes the paper and prospects the technology of content switching for future research.