A Study Of Support Software System Architecture And Vital Technology For High-Performance IPv6 Router

High-performance router is one of the kernel equipments in core network, openness and generalization of its software system has become a universal requirement of design. Based on the project of national 863 program-"Basic Platform and Experimental System of High-Performance IPv6 Router", this paper analyzes development trends of high-performance router support software architecture, makes a deep study of design principles and implementation methods of support software, presents design scenario of support software architecture- Hardware Abstraction Layer. This paper studies the vital technologies of implementing it in IPv6 router and designs the testing plan. The results of analyzing its functions show that Hardware Abstraction Layer has resolved the problems of high-performance router distributed architecture in aspects of generalization, openness and extensibility. The testing results fill the requirements of performance in IPv6 Router.This paper includes several aspects of content below:1. Review the evolvement course of high-performance router architecture, summarize that high-performance router has some characteristics, such as distributed architecture, multiple service functions, diversification implementation methods and general basic platform. Point out that the design goal of high-performance router support software is to devise a kind of software architecture which is extensible, independent of hardware implementation scenario, to construct open and general router software platform.2. Present the concept and design idea of Hardware Abstraction Layer, this is the solution of high-performance router support software. Hardware Abstraction Layer has three models of internal communication, virtual driver and equipment management. Internal communication lies at the end of Hardware Abstraction Layer, and is used to cover distributed hardware architecture of router. Virtual driver and equipment management are both at the upper layer of internal communication. The former abstract receive and send actions of line interfaces and its state, the latter manage and control the work circumstance of subordinate process units.3. Study the vital technology of implementation of Hardware Abstraction Layer in Linux system. It has several aspects of whole working mechanism, guarantee of real time, guarantee of high availability and guarantee of reliability. The whole working mechanism of Hardware Abstraction Layer has characteristic of block building link mechanism and poll looking up table. We guarantee its real time character through two vital technologies which named "real time TCP transfer method based on separator" and "block data exchange mechanism between kernel space and user space based on address mapping". Guarantee of high availability includes "internal communication possesses good flow control mechanism", "abnormal eventsannouncement based on keepalive detection" and "dynamic loading mode of virtual driver". Guarantee of reliability mostly depends on reliability of internal communication.4. Test the performance of the implemented Hardware Abstraction Layer in High-Performance IPv6 Router and analyze its functions. From the results, we can see that average transfer delay and packet lost rate locate are at a very low level under different network load. They can absolutely fill the requirements of efficiency and reliability in high-performance router.