Research And Implementation Of PIM-SM Protocol On Forces Router

To better satisfy the requirements of openbility to Next Generation Network (NGN), ForCES working group in IETF routing area, has proposed an open programmable routers architecture with the physical separation of the Forwarding Element (FE) and the Control Element (CE).IP multicast technic implements the data transfer from one point to multi-point, which can save the network bandwidth and decrease traffic.PIM-SM is a multicast route protocol which has been applied widely.A method to divide PIM-SM functions has been put forward under the ForCES architecture, through analizing the principle and features of PIM-SM. At the same time, to let the PIM-SM work correctly, method to maintain the states of PIM-SM has been proposed, which is based on ForCES event mechanism. To improve PIM-SM's work efficiency, we also mend the way to generate the events, such as: KAT setting, SPTbit updating and assert processing.Two LFBs which are concerned with multicast have been modeled according the ForCES FE model. Thay are PIM-SM LFB and the General Multicast Forwarding LFB (GMF LFB). The GMF LFB implements copying and L2 capsulating functions for the multicast packets, and it must exisit if the system supports multicast forwarding. PIM-SM LFB implements functions of multicast route managing and searching, and it must exisit if the system supports the PIM-SM protocol.A detailed design scheme to implement the PIM-SM on ForCES router has been raised on the basis of above researching and analyzing.Finally, the correctness of the solutions for some key technical problems and the two LFBs, the validity of the design scheme all had been verified by the experiments.