Deploying Safe UserLevel Network Services with icTCP

6th Symposium on Operating Systems Design & Implementation

Haryadi S. Gunawi ; Andrea C. Arpaci-Dusseau ; Remzi H. Arpaci-Dusseau

PID  :  75337

来源: CEUR

【 摘 要 】

We present icTCP, an “information and control” TCP implemen tation that exposes key pieces of internal TCP state and allows certain TCP variables to be set in a safe fashion. The primary benefit of icTCP is that it enables a variety of TCP extensions to be implemented at userlevel while ensuring that extensions are TCPfriendly. We demonstrate the utility of icTCP through a collection of case studies. We show that by exposing infor mation and safe control of the TCP congestion window, we can readily implement userlevel versions of TCP Vegas, TCP Nice, and the Congestion Manager; we show how userlevel libraries can safely control the duplicate acknowledgment threshold to make TCP more robust to packet reordering or more appropri ate for wireless LANs; we also show how the retransmission timeout value can be adjusted dynamically. Finally, we find that converting a stock TCP implementation into icTCP is relatively straightforward; our prototype requires approximately 300 lines