The last several years has seen a renewed interest in smart queue management to curb excessive network queueing delay, as people have realised the prevalence of bufferbloat in real networks. However, for an effective deployment at today's last mile connections, an improved queueing algorithm is not enough in itself, as often the bottleneck queue is situated in legacy systems that cannot be upgraded. In addition, features such as per-user fairness and the ability to de-prioritise background traffic are often desirable in a home gateway.In this paper we present Common Applications Kept Enhanced (CAKE), a comprehensive network queue management system designed specifically for home Internet gateways. CAKE packs several compelling features into an integrated solution, thus easing deployment. These features include: bandwidth shaping with overhead compensation for various link layers; reasonable DiffServ handling; improved flow hashing with both per-flow and per-host queueing fairness; and filtering of TCP ACKs. Our evaluation shows that these features offer compelling advantages, and that CAKE has the potential to significantly improve performance of last-mile internet connections.
ACK thinning refers to the technique to discard or reduce TCP acknowledgements (ACKs) for the purpose of diverting scarce bandwidth to TCP data traffic. Delayed ACK and ACK filtering fall into the category. It has been shown that under some circumstances the technique is effective to boost the TCP throughput on wireless links, in particular the IEEE 802.11 wireless LAN (WLAN). In this paper, however, we show that ACK thinning backfires under congestion due to its cross-layer impact on the 802.11 MAC dynamics. With the ACK filtering example, we demonstrate the phenomenon and analyze the cause. Based on the analysis, we show how the IEEE 802.11 contention window size control solves the problem. Although only the ACK filtering and Delayed ACK are considered in this paper, any other techniques to save on TCP ACK bandwidth usage share the same fundamental issues. Industry standard Data Over Cable Service Interface Specification (DOCSIS™) cable modems provide end users with an always-on, broadband connection to the Internet. Most applications delivered via that high-speed connection are transmitted via transmission control protocol (TCP). The interaction that takes place between TCP and the DOCSIS-defined media access control (MAC) protocol can have a negative impact on the performance of certain applications, and, as a result, negatively affect end users’ experience with those applications. This article discusses the inherent bi-directional behavior of TCP and its performance when used in conjunction with the DOCSIS MAC protocol. It provides typical examples of degradation in TCP throughput and describes how the addition of application awareness and acknowledgment filtering software can be used to improve TCP throughput. We study the effects of bandwidth asymmetry on end-to-end TCP performance and suggest a mechanism to improve it. Bandwidth asymmetry has been considered a mismatch in the bandwidths in two directions of data transfer. It is common in wireless networks, ADSL networks, etc. In a bandwidth asymmetry network, throughput achieved is not only dependent on the traffic and link characteristics of the forward direction, but significantly determined by those of the backward direction. Some mechanisms, has been proposed to overcome this problem. In our study, we focus on the ACK filtering algorithm, which decrease the rate of ACK on a constrained reverse link, taking advantage of the fact that TCP ACKs are cumulative.