QoS routing schemes for supporting load balancing

An efficient QoS routing scheme needs to find a path that satisfies a given QoS requirements while consuming as few resources as possible. As for global network utilization, the simple but effective criterion of hop minimization is used in many existing QoS routing schemes. In this paper, we propose two schemes for calculating resource costs one for on-demand and one for precomputation QoS routing schemes. These schemes are effective in respect to the global network utilization and the balanced use of network resources. We also propose a QoS routing scheme for transit and intra traffic in a large scale domain-based network. For a domain in the network, the routing scheme first precomputes K multiple paths between all pairs of ingress and egress border routers while considering balancing of the expected load. We, therefore, expect that the paths are better than any other paths in respect to reserving the network resources on paths. The routing scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme. Note that our cost calculation schemes for both kinds of traffic could be used in existing QoS routing protocols without any modification in small and large scale networks.