Can ISPs Take the Heat from Overlay Networks ?

ISPs manage performance of their networks in the presence of failures or congestion by employing common traffic engineering techniques such as link weight settings, load balancing and routing policies. Overlay networks attempt to take control over routing in the hope that they might achieve better performance for such failures or high load episodes. In this paper, we examine some of the interaction dynamics between the two layers of control from an ISP’s view. With the help of simple examples, we illustrate how an uncoordinated effort of the two layers to recover from failures may cause performance degradation for both overlay and non-overlay traffic. We also show how current traffic engineering techniques are inadequate to deal with emerging overlay network services.