@article {18534, title = {A Narrow Waist for Multipath Routing}, year = {2009}, month = {2009///}, institution = {School of Computer Science, Georgia Tech}, abstract = {Many applications can use multipath routing to improvereliability or throughput, and many multipath routing pro- tocols exist. Despite this diversity of mechanisms and applications, no common interface exists to allow an ap- plication to select these paths. This paper presents a de- sign for such a common interface, called path bits. Path bits are a small string of opaque, semantic-free bits in a packet header; these bits have a simple property: changing a packet{\textquoteright}s path bits should, with high probability, result in the packet taking a different path to the destination. This paper presents the design of path bits and demonstrates that they are simple enough to be easily implemented in both hardware and software and expressive enough to sup- port a variety of applications that can benefit from mul- tipath routing. We present both hardware and software implementations of multipath routing protocols that im- plement the path bits abstraction, as well as implementa- tions of applications that can use this abstraction with only small modifications. }, author = {Motiwala,M. and bin Tariq,M. and Anwer,B. and Andersen,D. and Feamster, Nick} }