Tanya Shreedhar

We present the age control protocol ACP+, a transport layer protocol that regulates the rate at which update packets carrying information from a source are sent over the Internet to a monitor. The source would like to minimize the average age of information at the monitor. Extensive experimentation helps shed light on age control over the current Internet and its implications for sources sending updates over a shared wireless access to monitors in the cloud. Surprisingly, age minimizing rates over fast Internet paths are about 0.5 Mbps, which is a small fraction, for example, of link rates supported by WiFi wireless access technology. We also show that congestion control algorithms employed by the Transmission Control Protocol (TCP), including hybrid approaches that achieve higher throughputs at lower delays than traditional loss-based congestion control, are unsuitable for age control.

QUIC was launched in 2013 with a goal to provide reliable, connection-oriented and end-to-end encrypted transport and is recently standardized in May 2021 by the Internet Engineering Task Force (IETF). This work evaluates QUIC performance over the web, cloud storage, and video workloads and compares them to traditional TLS/TCP. We target Alexa Top-1M websites and measure approximately 5.7K websites that support QUIC. We observe that QUIC has approximately 140% lower mean connection times than TLS 1.2/1.3 over TCP for low-bandwidth and high-RTT networks. For cloud storage, TLS 1.2 over TCP exhibits higher throughput for larger file sizes (>20 MB), while QUIC exhibits higher throughput for smaller file sizes. For video workloads, QUIC tends to depict better content delivery with reduced stall events and up to 50% lower stall durations due to its lower latency overheads.

The transport layer is ossified. With most of the research and deployment efforts in the past decade focussing on the Transmission Control Protocol (TCP) and its extensions, the QUIC standardization by the Internet Engineering Task Force (IETF) is to be finalized in early 2021. In addition to addressing the most urgent issues of TCP, QUIC ensures its future extendibility and is destined to drastically change the transport protocol landscape. In this work, we present a first look at emerging protocols and their IETF standardization efforts beyond QUIC v1. While multiple proposed extensions improve on QUIC itself, Multiplexed Application Substrate over QUIC Encryption (MASQUE) as well as WebTransport present different approaches to address long-standing problems, and their interplay extends on QUIC’s take to address transport layer ossification challenges.