Design And Implementation Of The Software System For Switch In Ethernet Passive Optical Network System

EPON (Ethernet Passive Optical Network) is a new Network technique which uses point-to-Multipoint structure and transmits through passive fiber. It aims to solve the "last mile" bottleneck, which has the characteristic of low cost and good compatibility, and its technology has been developed well. Therefore EPON has a fairly wide market. Layer 2 multicasting and VLAN are one of two necessary applications in both EPON Network and other access networks. In the application of access network, VLAN can supply the method to partition the final users, reduce the unnecessary load on network, improve the performance and the efficiency of the whole system. Layer 2 multicasting can effectively provide the flow control of multicast packet so as to save the network bandwidth .This paper mainly presents the design and implementation of software and hardware for EPON. The implementation details of EPON software&hardware system is introduced with six chapters, the main work is as below:1. Optical signal can transmit to terminal users accurately without complex protocol in EPON system. Considering from systematic structure of EPON , EPON systematic composition and characteristic were analysed and the embedded technology application and characteristic in this system are analysed. OUN and OLT in EPON are both typical layer 2 switching equipment, the function structure of layer 2 Ethernet switch are analysed, the common software platform of layer 2 Ethernet switch are provided,moreover , the key agreement of IEEE802.1 standard are analysed.2. Provideing the implementation of software from the analysis of ASIC performance. The embedded system is based of the Powerpc 8241 CPU, and select two kinds of switch engines BCM5645&BCM5691.CPU provides the control for switch ASICs through PCI bus.3. The paper comes up with the whole framework of EPON system software from the demand. The design of the software system involves the porting of the chip driver in the Operating System mainly and the realization of system management.Analyzing detailedly the concrete implementation of the VLAN and Layer 2 multicasting , designing the corresponding data structure which accords with the systematic request and controlling software. Test and analysis is performed on the prototype system. It turns out the software system works correctly.