Poster: Evaluating Android Applications with Multipath TCP

Smartphones are the most popular mobile multihomed devices. End-user expects that thanks to their WiFi and cellular interfaces, they are able to seamlessly use all available networks. Unfortunately, reality tells us that seamless coexistence between cellular and WiFi is not as simple as what the user expect. Several cellular/WiFi coexistence technologies have been proposed during the last years. Some of them have been deployed. Recently, Multipath TCP received a lot of attention when it was selected by Apple to support its voice recognition (Siri) application. As of this writing, Siri is the only deployed smartphone application that uses Multipath TCP. and there is no public information about the benefits of using Multipath TCP with it. Multipath TCP is a TCP extension that allows to send data from one end-to-end connection over different paths. On a smartphone, Multipath TCP allows the applications to simultaneously send and receive data over both WiFi and cellular interfaces. It achieves this objective by establishing one TCP connection, called subflow, over each interface. Once the subflows have been established, data can be sent over any of the subflows. Researchers have analyzed the performance of Multipath TCP in such hybrid networks. However, these analyses have been performed with bulk transfers between laptops and servers. As of this writing, no detailed analysis of the performance of real smartphone applications with Multipath TCP has been published. We fill this gap in this paper by proposing a framework that automates user actions on Android smartphone applications to perform network measurements. We use it to analyze how eight popular smartphone applications interact with Multipath TCP.