An efficient flow control approach for TCP over wireless networks

Recently, mobile and wireless devices are being incorporated to the Internet at a rapid pace. 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 from 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 acknowledgment. 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.