LCR solution for performance and cost-efficient inter-domain traffic distribution

In the highly connected Internet most of domains have more than one interconnection link to different providers. In such a multi-homed scenario destinations for inter-domain traffic may be reachable through multiple egress routers with different offered cost and path performance. In this paper, we address the problem of route selection in a multi-homed stub network to optimize transit costs and paths performance offered by operator to its customers. As the indicators of quality of service (QoS) related to interconnections and routes offered by interconnected partners we consider a length of AS-path (Autonomous System) and latency experienced on that path as measured by round-trip-time (RTT). We present some QoS optimization models together with heuristic algorithms to solve the problem. To evaluate the performance of the proposed optimization models a Least Cost Routing (LCR) solution supporting optimal routing decisions has been used. The results indicate that taking into account both cost and performance is crucial for assuring the satisfied level of service for end-users with optimized cost for the operator.