Journal of Theoretical and Applied Information Technology
The delay-based congestion control mechanism performs well over the bandwidth-symmetric network rather than bandwidth-asymmetric network. The upstream and downstream link of asymmetric network has different bandwidth i.e. high bandwidth in the downstream link and low bandwidth in the upstream link. Therefore, mostly the bottleneck link is the upstream link, not the downstream link. Therefore, even if the downstream link of data flow is uncongested, congestion in the upstream link can disrupt the acknowledgement flow. Even if ACKs are smaller in size than data packets, the upstream link is unable to carry the high rate of ACKs.