Research On Routing Optimization Issues Based On Traffic Balancing

The shortest-path-first routing mode in traditional IP routing protocols easily leads to create congestion in the hot-spot links, and relatively leisure of other links. Therefore, based on the traditional route, strengthening the control ability of routing algorithms, to balance the distribution of traffic is one focus of the routing optimization problem study.Combined with the national 863 project―a multi-next-hop routing mechanism based on node potential orientation‖, this dissertation analyzed the existing technologies of traffic balancing, and then proposed route optimization problem strategy. The Equal-Cost-Multi-Path in OSPF protocol which has multiple paths, is optimized firstly; then the candidate path set was extended, and the routing optimization problem under the Multi-next-hop routing mechanism was studied. At last a routing switching algorithm to avoid the routing congestion of links was proposed. To sum up, the main work is as follows:1. A link-criticality-based ECMP routing algorithm, named LCER, was proposed. The algorithm selected a specific path with relatively light average load to forward the traffic, according to the task in the network, so as to minimize the interference between the node pairs. Single path forwarding avoids the out of order problem caused by multi-path forwarding. Simulation results show that LCER algorithm could aviod the interference on the hots-pot links, achieve better performance of throughput, average delay and packet in order than random selection and traffic splitting algorithm.2. Combined with the optimization objective of reducing the network consumption and avoiding the interference between the routing requests this paper proposed a multi-next-hop routing algorithm based on distance-and-link-criticality, named DLCR. Simulation results show that the algorithm could achieve better performance in decrease packet-loss-ratio, and increase network throughput, and played a certain role in avoiding interference because the utilization of hot link was decreased than other algorithms. Parameter can be set flexibly according to different optimization objectives.3. An online routing switching algorithm is designed to avoid the link congestion. This algorithm was a complement of DLCR. To avoid route oscillation caused by frequent routing switch and serious out of order problem caused by traffic splitting, the strategy of the algorithm made strict definition of switching time. The analysis demonstrated that under the premise of that the message length is greater than the maximum of all path delay difference, the receiver can avoid out of order problem. Simulation results show that the algorithm could mitigate packet loss caused by competition of network resources, significantly increased network throughput, and made a markedly improvement on the distribution of the network traffic, compared with the DLCR algorithm.