Summary: A Comparison of Overlay Routing and
Multihoming Route Control 1
Aditya Akella 2 Jeffrey Pang 2 Anees Shaikh 3
Bruce Maggs 2 Srinivasan Seshan 2
August, 2004
CMU­CS­04­158
School of Computer Science
Carnegie Mellon University
Pittsburgh, PA 15213
Abstract
The limitations of BGP routing in the Internet are often blamed for poor end­to­end performance and prolonged con­
nectivity interruptions. Recent work advocates using overlays to effectively bypass BGP's path selection in order to
improve performance and fault tolerance. In this paper, we explore the possibility that intelligent control of BGP
routes, coupled with ISP multihoming, can provide competitive end­to­end performance and reliability. Using exten­
sive measurements of paths between nodes in a large content distribution network, we compare the relative benefits
of overlay routing and multihoming route control in terms of round­trip latency, TCP connection throughput, and
path availability. We observe that the performance achieved by route control together with multihoming to three ISPs
(3­multihoming), is within 3--12% of overlay routing employed in conjunction 3­multihoming, in terms of both end­to­
end RTT and throughput. We also show that while multihoming cannot offer the nearly perfect resilience of overlays,
it can eliminate almost all failures experienced by a singly­homed end­network. Our results demonstrate that, by

Source: Akella, Aditya - Department of Computer Sciences, University of Wisconsin at Madison
Carnegie Mellon University, School of Computer Science

Collections: Computer Technologies and Information Sciences