Wednesday, August 14, 2013

SIGCOMM13: Trinocular: Understanding Internet Reliability through Adaptive Probing.

Presenter: Lin Quan

This paper studies the Internet outages by using Trinocular which relies on the detection of three states (up, down, and uncertain). Authors argue that outages are mainly due to three reasons: Political, weather, and Infrastructure. These outages are equally important for users, network operators, and researchers.

Trinocular uses active probes to study the reliability of the Internet edges. Probes are only sent when needed and the additional increase in the Internet radiations is less than 0.7%. Multiple instance of Trinocular are used to detect global outages. The probing interval is around 11 minutes and sends less than 20 probes per /24 network. Trinocular relies on Baysian inference to decide how many probes are necessary to send.

The main take away is that Trinocular is precise and significantly more accurate than the existing methods. For details check out the paper at

Q: Have you differentiated between outage and a powered off host.
A: No, we cannot differentiate.

Q: Why it is called Trinocular?
A: Because it has three states, up, down, and uncertain.