Research And Implementation Of Rapid Spanning Tree Protocol In Ethernet Switch

Spanning Tree Protocol is the basic protocol of network equipment in Layer Two. It makes the structure of network's active topology like a tree by complicated computing. So it can avoid network storm brought by loops and repeated receiving of frame. From the STP to RSTP and then MSTP etc, many spannmg tree protocol come into being. The speed of active topology constringency is more and more rapid. Normal switch or bridge has implemented STP, which can constringe in several ten seconds and it need little system resource. STP can satisfy most application of network. But going with the development of network's velocity and the application of multimedia, this time is oppressive to the user. To resolve this problem, many factories of switch take special technology, but their products are short of compatibility. In this case, the committee of IEEE standard begins to establish the RSTP standard, it is named 802. lw standard document, the time of constringency is several second. Now it is the main technology of spanning tree protocol. In some advanced switch it gets wide application. This thesis bases on actual product of switch, expatiates RSTP systemic and embedded. And it introduces detailed the implemention of RSTP on specifically platform. My main work as follows:1. Introduce the hardware and software environment (switch, VxWorks RTOS, TMS2.0 package).2. Analyze the theory of RSTP, including theory, state machine, advantage, and defect. Give a model of 8 nodes LAN to simulate. Explain the process of active topology coming into being.3. Introduce the implemention of RSTP, including model design, data structure design and sub- procedure design etc. Especially the interface between RSTP and other modules.4. Analyze this implemention, bring forward a method of enhancement, and give the test.