A measurement-based study of MultiPath TCP performance over wireless networks

Abstract

With the popularity of mobile devices and the pervasive use of cellular technology, there is widespread interest in hybrid networks and on how to achieve robustness and good performance from them. As most smart phones and mobile devices are equipped with dual interfaces (WiFi and 3G/4G), a promising approach is through the use of multi-path TCP, which leverages path diversity to improve performance and provide robust data transfers. In this paper we explore the performance of multi-path TCP in the wild, focusing on simple 2-path multi-path TCP scenarios. We seek to answer the following questions: How much can a user benefit from using multi-path TCP over cellular and WiFi relative to using the either interface alone? What is the impact of flow size on average latency? What is the effect of the rate/route control algorithm on performance? We are especially interested in understanding how application level performance is affected when path characteristics (e.g., round trip times and loss rates) are diverse. We address these questions by conducting measurements using one commercial Internet service provider and three major cellular carriers in the US.

Is multi-path transport suitable for latency sensitive traffic?

“…For MPTCP, a closely related research work is [72], which measures MPTCP performance with the aim to understand the benefit of using two interfaces with MPTCP over using either one of the interface with TCP. This study also focuses on the impact that flow size has on the average latency, and provides insights into the effect of path characteristic diversity on application level performance.…”

Use Cases and Operational Experience with Multipath TCP

“…It compares various file transfer scenarios. [IMC13b] observes that 4-path MPTCP outperforms 2-path MPTCP, especially for larger files. However, for three congestion-control algorithms (LIA, OLIA, and Reno --see Section 3.2), there is no significant performance difference for file sizes smaller than 4 MB.…”

“…Another study of the performance of Multipath TCP in wireless networks was reported in [IMC13b]. This study uses laptops connected to various cellular ISPs and WiFi hotspots.…”

On the benefits of applying experimental design to improve multipath TCP

“…Flow control provides another limitation to the sending rate. Many external factors further influence the performance of MPTCP [20,4,19,6]. Especially the network's characteristics in terms of capacity, propagation delay, etc.…”