Online traffic engineering: the least interference optimization algorithm

Flow-based routing algorithms using a priori knowledge of the ingress-egress pairs to reduce LSP rejection in MPLS networks have recently been proposed as improvements to the destination-based routing model currently deployed in the Internet. These traffic-aware algorithms incur additional complexity which does not necessarily translate into equivalent performance gains. This paper presents a new routing scheme referred to as least interference optimization (LIO) where the online routing process uses the current bandwidth availability and the traffic flow distribution to achieve traffic engineering in IP networks. A least interference optimization algorithm (LIOA) is presented which reduces the interference among competing flows by balancing the number and quantity of flows carried by a link to achieve efficient routing of MPLS bandwidth-guaranteed LSPs. Initial simulation results show that LIOA performs better than several well known routing algorithms such as the minimum hop algorithm (MHA), open shortest path first (OSPF), constraint shortest path first (CSPF) and minimum interference routing algorithm (MIRA) in terms of several performance parameters including the LSP rejection upon congestion, the successful re-routing of LSPs upon single link failure and the ease of implementation.