A study of email usage and performance over Cellular technology

In this paper we investigate the performance of Cellular networks, focusing on the key mail and webmail services. Specifically, the primary motivation of this research is to compare mail and webmail performance and to discuss different factors that affect performance as perceived by end users. We discuss key factors related to the network configurations, e.g., proxies, that can bias the computation of performance metrics, e.g., RTT. For Webmail, we are able to further characterize webmail servers and client devices including the operating systems (OS) of the devices. In our trace, Hotmail is the most popular service and represents 23% of all webmail connections. As for users' device, the Iphone of Apple drives the market and thus appears by far the most commonly used end user device. While mail generates more TCP connections than webmail, it represents less bytes. We show that webmail achieves higher throughputs than legacy mail. We investigate this difference of throughputs and uncover several key factors that explain this difference. In particular, we demonstrate that while losses can have a detrimental impact for both mail and webmail, it impacts more the former. Also, the mail application (mail client and server) significantly impacts the way data is exchanged and thus the throughput.