Research On And Design Of Scheduler And Queue Management In Private Router

It is a different method to design an astronautic router from the one on the ground. It requires more balance in functionality, security, stability and performance. A good scheduling mechanism can guarantee a switching processing service flow fairly and achieving high throughput rate relatively, moreover, it is frequently combined with the queue management. This thesis researches the project, “ Design of Switching Unit in Private Router with hybrid circuit and packets”, which has been undertaken by our laboratory, and aims at demand for the design of the project to implement its function. Further balanced scheduling mechanism and queue management will be chosen to satisfy demand. A simulation result of the scheduler and the queue management will be shown. A procedure and conclusion of the joint debugging of private router will be given.This thesis introduces research background of the project firstly, meanwhile, the status of development and key techniques of switching fabric are also shown. Then, the scheduling mechanism and buffer management in single path switching based on the current status of the research are discussed. This thesis introduces the topological structure of the router system next and proposes a series of scheme to solve the problems, which the special demand and limitation of payload cause. In chapter 4, we emphatically deal with the implementation of scheduler and queue management in private router. The scheduler can be divided into two part: receiving scheduler and transmitting scheduler. The receiving scheduler doesn’t only schedule the frame from all ports timely but also achieves the security mechanism which filters malicious frame. The transmitting scheduler uses 3-step scheduling to output the frame from all physical port, logical port and priority of queue fairly. The queue management manages the read and write operations with fairness. A special implementation of scheduler is proposed to operate the multicast traffic. Finally, a simulation and a test on circuit board are accomplished to verify the design. The results show the methods can satisfy the demand for design on the existing conditions. In the conclusion and prospect, we evaluate the existing switching unit in resource, performance, fairness and operation of multicast traffic, and then propose modified scheme.