Improving TCP throughput over two-way asymmetric links: analysis and solutions
SIGMETRICS '98/PERFORMANCE '98 Proceedings of the 1998 ACM SIGMETRICS joint international conference on Measurement and modeling of computer systems
Two-way TCP traffic over rate controlled channels: effects and analysis
IEEE/ACM Transactions on Networking (TON)
The effects of asymmetry on TCP performance
Mobile Networks and Applications
Improving TCP performance in residential broadband networks: a simple and deployable approach
ACM SIGCOMM Computer Communication Review
Scalable Multi-purpose Network Representation for Large Scale Distributed System Simulation
CCGRID '12 Proceedings of the 2012 12th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (ccgrid 2012)
Investigating the interacting two-way tcp connections over 3GPP LTE networks
Proceedings of the 15th ACM international conference on Modeling, analysis and simulation of wireless and mobile systems
On the validity of flow-level tcp network models for grid and cloud simulations
ACM Transactions on Modeling and Computer Simulation (TOMACS)
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Many papers explain the drop of download performance when two TCP connections in opposite directions share a common bottleneck link by ACK compression, the phenomenon in which download ACKs arrive in bursts so that TCP self clocking breaks. Efficient mechanisms to cope with the performance problem exist and we do not consider proposing yet another solution. We rather thoroughly analyze the interactions between connections and show that actually ACK compression only arises in a perfectly symmetrical setup and it has little impact on performance. We provide a different explanation of the interactions---data pendulum, a core phenomenon that we analyze in this paper. In the data pendulum effect, data and ACK segments alternately fill only one of the link buffers (on the upload or download side) at a time, but almost never both of them. We analyze the effect in the case in which buffers are structured as arrays of bytes and derive an expression for the ratio between the download and upload throughput. Simulation results and measurements confirm our analysis and show how appropriate buffer sizing alleviates performance degradation. We also consider the case of buffers structured as arrays of packets and show that it amplifies the effects of data pendulum.