An approach for efficient TCP flow control over wireless links

Wireless devices are rapidly becoming indispensible parts of the Internet. This initiates the need for optimizing major applications to perform satisfactorily over wireless links. TCP performance over wireless networks is affected by high link errors, low bandwidth and large delay. Existing well established solutions like the Eifel algorithm, TCP I&RW, TCP SACK and D-SACK attempt to address these issues. However, Eifel or TCP I&RW suffer in the presence of ACK losses, while TCP SACK or D-SACK introduce overhead in addition to failure in the presence of multiple packet loss. In this paper, we propose a scheme that overcomes the above problems by introducing a concept of indirect acknowledgement. We name this scheme as TCP IACK. Our proposal exploits TCP timestamp option as an additional identifier to TCP segments for the purpose. Furthermore, it deploys one padding byte following TCP timestamp option to recover from ACK loss. Our proposal is therefore, lightweight, more efficient and robust than existing approaches. We also verify these performance implications through experiments.