Coexistence of Age Sensitive Traffic and High Throughput Flows: Does Prioritization Help?

TL;DR

This paper investigates whether prioritization techniques improve the timely delivery of status update flows in networks sharing high throughput traffic, especially under WiFi contention, revealing limitations of current methods.

Contribution

It provides real-world experimental insights into the effectiveness of prioritization schemes for status updates in mixed traffic environments, highlighting their limitations under WiFi contention.

Findings

Prioritization isolates flows without WiFi contention.

Contention reduces prioritization effectiveness.

Status update age remains high despite prioritization.

Abstract

We study the coexistence of high throughput traffic flows with status update flows that require timely delivery of updates. A mix of these flows share an end-to-end path that includes a WiFi access network followed by paths over the Internet to a server in the cloud. Using real-world experiments, we show that commonly used methods of prioritization (DSCP at the IP layer and EDCA at the 802.11 MAC layer) in networks are highly effective in isolating status update flows from the impact of high throughput flows in the absence of WiFi access contention, say when all flows originate from the same WiFi client. Prioritization, however, isn't as effective in the presence of contention that results from the throughput and status update flows sharing WiFi. This results in prioritized status update flows suffering from a time-average age of information at the destination server that is about the same as when all flows have the same priority.