On Reducing the Impact of Interdomain Route Changes

Abstract

Interdomain route changes are frequent and they can have negative impact on a network’s operation: during route convergence, packets get delayed and dropped; after route convergence, changes in the egress point for reaching a destination can alter the network’s intradomain traffic patterns and trigger new traffic-engineering. In this paper, we look into reducing the impact of interdomain route changes on the network’s operation. First, we investigate a route decision process which avoids the selection of routes that cause egress point changes. However, this decision process does not consider the potential benefit of selecting a more preferred route even if it causes an egress point change. Then, we propose a system which only avoids route changes causing recurring intradomain traffic shifts by processing the route changes history and by selectively modifying route attributes which affect the route decision process. We evaluate both approaches using data from a major European ISP. The modified route decision process avoids 89% of the observed intradomain traffic shifts caused by interdomain route changes, whereas route attribute modifications reduce the number of traffic shifts on average by 25%, and as much as 50%.