Blink: Fast Connectivity Recovery Entirely in the Data Plane


Thomas Holterbach, Edgar Costa Molero, and Maria Apostolaki, ETH Zurich; Alberto Dainotti, CAIDA / UC San Diego; Stefano Vissicchio, UC London; Laurent Vanbever, ETH Zurich


In this paper, we explore new possibilities, created by programmable switches, for fast rerouting upon signals triggered by Internet traffic disruptions. We present Blink, a data-driven system exploiting TCP-induced signals to detect failures. The key intuition behind Blink is that a TCP flow exhibits a predictable behavior upon disruption: retransmitting the same packet over and over, at epochs exponentially spaced in time. When compounded over multiple flows, this behavior creates a strong and characteristic failure signal. Blink efficiently analyzes TCP flows, at line rate, to: (i) select flows to track; (ii) reliably and quickly detect major traffic disruptions; and (iii) recover data-plane connectivity, via next-hops compatible with the operator’s policies.

We present an end-to-end implementation of Blink in P4 together with an extensive evaluation on real and synthetic traffic traces. Our results indicate that Blink: (i) can achieve sub-second rerouting for realistic Internet traffic; (ii) prevents unnecessary traffic shifts, in the presence of noise; and (iii) scales to protect large fractions of realistic Internet traffic, on existing hardware. We further show the feasibility of Blink by running our system on a real Tofino switch.

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@inproceedings {227629,
author = {Thomas Holterbach and Edgar Costa Molero and Maria Apostolaki and Alberto Dainotti and Stefano Vissicchio and Laurent Vanbever},
title = {Blink: Fast Connectivity Recovery Entirely in the Data Plane},
booktitle = {16th {USENIX} Symposium on Networked Systems Design and Implementation ({NSDI} 19)},
year = {2019},
isbn = {978-1-931971-49-2},
address = {Boston, MA},
pages = {161--176},
url = {},
publisher = {{USENIX} Association},