Effective Bandwidth Utilisation in Multihoming Networks

In order to bridge the speed disparity at the LAN-WAN interface, enterprises install a number of policy-based devices to enforce administrative policies over the WAN access. The conventional techniques of bandwidth management concentrate only on the outgoing traffic from the local network, since that is the only traffic that can be controlled. However it is usually the incoming traffic that causes bottlenecks. This paper proposes a simple load balancing approach to optimize the use of WAN links in a multihomed environment. Incoming traffic on a link is controlled by diverting outgoing traffic from some nodes to other links. Incoming bandwidth is measured, thresholds are defined, and traffic diversion takes place to maintain the thresholds. We present a scheme to implement this. A prototype implementation has been done on an educational campus network. Preliminary experiments have shown that there are significant improvements in performance. These results are presented. Proposed future work to extend the scheme to an ISP network is described