Characterizing and reducing route oscillations in the Internet
Oscillation of routes in the Internet causes unnecessary overhead. Border Gateway Protocol (BGP) transactions collected from the MAE-East exchange point for 2000 (January-December) show that approximately 16% of routing overhead traffic exhibits oscillating Autonomous System paths. About 66% of these paths used extra, unnecessary hops to route data traffic resulting in up to 10% extra-hop count. Common characteristics are shown to exist in oscillating routes. Our findings demonstrate that long-theorized route oscillations really do occur in the Internet. Faulty implementations and/or poor policy choices are likely causes, where the currently specified method of BGP implicit withdrawals causes propagation through the Internet. To reduce oscillations, we propose a new method of forcing explicit withdrawals in BGP. Simulation experiments with forcing explicit withdrawals show an overall reduction of the transaction traffic, as well as a reduction in path length. (C) 2002 Elsevier Science B.V. All rights reserved.
routing route oscillation border gateway protocol route flap damping