Inbound traffic engineering for multihomed ASes using AS path prepending

Unlike outbound traffic, incoming traffic distribution to a multi-homed AS is influenced mainly by the upstream ISPs' routing policies. Currently, only a handful of mechanisms is available for such an AS to engineer the traffic volume coming into these links. In this paper, we concentrate on the problem of re-distributing the incoming traffic across the multiple links. We consider the approach of AS path prepending artificially inflates the length of the AS path to the network reported in BGP messages, with the hope of diverting some of the traffic from one incoming link to another. Although this approach has already been deployed by many ASes, they are often performed in a trial-and-error basis, and there also lacks a detailed measurement study on the effectiveness of this approach. This paper attempts to fill these gaps. In particular, we have proposed a complete procedure based on the AS path prepending method to engineer incoming traffic according to some traffic control policy. The procedure includes passive measurements, active measurements, and traffic change prediction. We have deployed this approach to a non-commercial site and evaluated its effectiveness based on the measurements collected over six months. Similar measurement cycles can be replicated in other multihomed ASes by deploying the procedure and the associated software tools.