Packet Sniffing in the Subway

What I learned from a week of sniffing packets and lurking around Wi-Fi access points in New York subway stations.

Jen Kagan
Jen Kagan
Mar 28, 2016 · 5 min read
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Photo by @taraadiseshan

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Screen shot from http://www.transitwireless.com/what-we-do/wifi-advertising/

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Anatomy of a Packet

Each line of text in the log represents information about a specific packet. It tells us about the device that sent the packet and the networks involved.

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From a Zebra Technologies marketing video

If You Were an Access Point, Where Would You Go?

I found the answer one morning in the voices of five burly, yellow-vested technicians who work for a company called VComm. They were rolling their equipment to different points of the Franklin C station as I lurked nearby.

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Subway stations with (green) and without (red) Wi-Fi, as of February 2016

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