Paper Review:
TCPVEgas: End to End Congestion Avoidance on a Global Internet

Reviewer: Jie Zhou


TCP is the dominant protocol in current Internet. Improving it's performance is of great importance.


The paper presents a new TCP implementation, Vegas, which adopts several techniques including a new timeout mechanism, a novel approach to congestion avoidance, and a modified slow-start mechanism. Compared to Reno, Vegas achieves better throughput and lower retransmition rate.

Main Ideas

  • Vegas decreases the retransmition rate by a more accurate scheme for timeout.
  • Vegas increases the throughput by a more efficient utilization of the bottleneck link.
  • Vegas does not cause fairness, stability or latency problem.


    I give the paper a rate 4 (significant contribution), because it provides a more effecient implementation of TCP which will improve the performance of the whole Internet.

    The paper is quite convincing. Besides clear theoretical explanation, the author also gives us extensive experiment data and analysis, both on simulator and real network.


  • A major advantage of Vegas over other appoaches is that: Vegas does not involve any changes to the TCP specification, so that it can interoperate with any other valid implementation of TCP.