Research On QoS Of Multi-nexthop Routing Mechanisms

With the fast development of audio and video real-time applications, much more requirement of QoS guarantee for data transmitting is needed. QoS guarantee for the next-generation Internet is a challenging problem, and it is also a hot-topic in Internet research. Based on multi-nexthop mechanism, this dissertation proposes a universal QoS solution scheme with general and distinguishing QoS guarantee for transport-layers. This scheme could provide universal QoS for various applications and achieve load balancing, making the high efficiency of network bandwidth utilization. The main work and contributions are outlined as follows:The dissertation puts forward a QoS performance index system for multi-nexthop. According to the system, a fast and effective evaluation for the otherness of different nexthop resource can be made, which provides proper selection evidence of nexthop for packet forwarding.Due to the issue of how to use the multi next hops to provide QoS guarantees, and combined with the scheme feasibility, the dissertation proposes a Link QoS Grade Mapping Strategy based on traffic types. The strategy classifies the next hop links, and forms the mapping relationship between traffic types and the classification of next hop links. It provides condition for achieving the forwarding of all kinds of data packages corresponding to the next hop links.To resolve the problem of network congestion and how to choose the best next hop link for different QoS requirements, the dissertation proposes a multi-nexthop QoS load balancing algorithm. The algorithm chooses the corresponding grade link from the set of the grade of next hop links to forward the data packages. It solves the problem of load balancing and achieves better QoS guarantee. The simulation results show that the multi-nexthop QoS load balancing algorithm forwards the data according to load of the node, and exhibit good performance.The dissertation designs a QoS implementing scheme, based on multi-nexthop routing mechanism. The scheme provides a general distinguishing Quality of Service to process the traffic in the network level, it satisfies the transmission demand of different QoS traffic, and guarantees the general processing of different kinds of data. The simulation results show that the scheme perform well in bandwidth, loss and delay.