Network Systems Group Princeton University   E2E Protocol Design

Project Goals

The goal of this work is to make end-to-end protocols (TCP in particular) more effective. Our approach is to both investigate opportunities to improve the congestion control algorithm used by transport protocols, and to explore the use of alternative end-to-end paths across the Internet.

Results

We have done a follow-up study of our earlier work on TCP Vegas in an effort to provide a theoretical model of its behavior. The model views Vegas congestion control as a global optimization problem, and shows how Vegas stabilizes around a weighted proportionally fair allocation of network capacity [JACM 2002].

We describe a variant of TCP, called mTCP, that aggregates the available bandwidth of multiple disjoint paths across the Internet. By striping one flow's packets across multiple paths, mTCP can not only obtain higher end-to-end throughput, but is also more robust under path failures [Usenix 2004].

We describe a variant of TCP, called RR-TCP, that uses the DSAK option to robustly reorder packets. By being able to accommodate packets that arrive out-of-order (without mistakenly concluding that there was packet loss) RR-TCP is able to take advantage of packets that have been sent in parallel across multiple disjoint paths [ICNP 2003].

People

Sally Floyd
Brad Karp
Steven Low
Larry Peterson
Limin Wang
Randy Wang
Ming Zhang