Research On Multi-Path Synthesis Method Based On MPLS Differentiated Service

With the rapid development of network technology, people need to the network increasing constantly, the emergence of various new services put forward higher quality of service of the network requirements. Multi-path routing can use the aggregation bandwidth of multi paths efficiently and improve the robustness of network, security, load balancing and quality of service. As a result, multi-path has attracted much attention in the routing and switching research fields and many important ideas and solutions have been proposed. Differentiated Services can be used to transmit different flows. Different business has different specific QoS, therefore, DiffServ and multi-path is the best method to implement QoS.Because of the majority of routing algorithm takes everything in one’s power for the same kind of businesses at the IP network, imputs forward Coarse-grained Differentiated Multipath Routing (CDMR) based on MPTCP in order to improve QoS. The core idea of CDMR is that when a link is selected by two kinds businesses at the same time, CDMR algorithm distributes the path to the real-time service. At the same time, best-effort business chooses other path in order to ensure the QoS of real-time service. Considering MPLS and DiffServ have similar forwarding mechanism, MPLS DiffServ has the problem of AF packet sequence. It raises a security multi-path algorithm for packet order invariant. That is Minimum Cost Multipath Routing Algorithm based on number (NMCM). The core idea of NMCM algorithm adds number to each AF service. It used to show the packet sequence and it is unique. The algorithm builds three different drop rate of LSP for the three drop priority AF business to distinguish priorities. Because of EF service has low delay and low jitter of the highest quality of service requirement; Most algorithms find an optimal transmission path. It present the multi-path routing algorithm based on link critical degree and saturation degree (CSMR). Not only the algorithm optimizes routing stategy, but also builds a plurality of LSP for EF. This algorithm is composed of off-line preprocessing stage and on-line routing stage. Off-line preprocessing stage according to the topological structure of the network identifies Link Critical Value for the link between source and destination node pair. On-line routing stage according to the network source determines the link saturation value. We first obtain the link cost function through adding the link ciritical value and the link saturation, and then we use the Dijkstra algorithm for the business route. Last but not least, the NS2 simulation shows multi-path of CDMR has obvious advantage. It also takes the corresponding routing method for the type of business to ensure real-time service QoS. NMCM considers the hop, bandwidth and minimum cost. It can improve the network throughput and reduce delay to guarantee the packet sequence of AF business. CSMR takes multi-path to transmiss EF business. It can improve the EF throughput and reduce average path length to protect the EF QoS.