Stefano Vissicchio

Lecturer @ UCL

s.vissicchio (at) cs (dot) ucl (dot) ac (dot) uk

University College London
Department of Computer Science
Gower Street
London, WC1E 6BT, UK

I have joined the Department of Computer Science at University College in October 2016, after 4 years as post-doctoral researcher at Universite catholique de Louvain in Belgium as well as 3 years as PhD student at Roma Tre University in Italy. More information on my background and achievements are reported in the About me page.

My research activity focuses on theory, algorithms and systems for efficiently and reliably managing communication networks. I believe in a rigorous approach to solve practical networking problems: In my research, I often leverage the insights gained by deep, theoretical analyses of formal network models and problem statements to design new algorithms and techniques -- and build fully-fledged system prototypes around them.

I currently have openings for PhD students. Successful candidates must pass the standard UCL admission process. If you are interested in working with me, don't hesitate to drop me an email!

News Research Overview Selected Publications Software


Latest updates on my professional activity.

  • May 2018: honored to have been a member of the PhD thesis committee of Renaud Hartert, from UCLouvain

  • May 2018: our paper on the interplay between intra-domain routing, topologies, and traffic variability has been accepted at SIGCOMM 2018!

  • April 2018: Olivier Tilmans has presented Stroboscope at NSDI 2018 (slides and video)

  • April 2018: participation in NSDI 2018 and INFOCOM 2018

  • March 2018: TPC member for INFOCOM 2019

  • December 2017: Stroboscope, our monitoring-on-a-budget system for ISPs, has been accepted at NSDI 2018!

  • December 2017: TPC member for SIGCOMM 2018

  • November 2017: participation in IMC 2017

  • October 2017: our position paper on low latency routing on "meshy" ISPs has been accepted at Hotnets 2017

  • October 2017: REPETITA, our proposal to ease repeatable experiments on traffic engineering algorithms (with data on more than 250 topologies, implementation of segmnent routing algorithms, and easy-to-run analyses), is publicly available: Check out our arXiv paper, and our GitHub repository!

  • August 2017: SWIFT has been presented at SIGCOMM, by Thomas Holterbach (Thomas' slides)

  • August 2017: participation in SIGCOMM 2017

  • June 2017: the extended version of our FLIP paper has been accepted to ToN

Research Overview

An overview of the main topics on which my research activity has focused.

  • Partially centralized networked systems: Theory, architecture and techniques to profitably combine centralized (SDN) and distributed (traditional) control-planes, for the greater good. Our contributions range from an overview of the research space (CCR11) and a general control-plane theory (INFOCOM15) to concrete architectures and techniques (like Fibbing, DEFO, and IBSDN).

  • Fine-grained monitoring: Architectures and systems for advanced monitoring and anomaly detection. Mainly, we proposed and assessed the feasibility of control-plane message collectors based on packet cloning (INM10), traffic-matrix estimators based on programmable routers (PRESTO10), warning systems for BGP policy violations (TNSM16), hardware-bug detectors exploiting segment routing (SCMon), and generic, fine-grained traffic monitoring systems for ISPs (Mille-feuille,Stroboscope).

  • Network updates: Complexity results, algorithms and systems to change packet-forwarding paths in a running network with guaranteed service continuity. We considered several network-update problems, in IGP-only (like SIGCOMM11 and ToN15a), BGP-running (see INFOCOM13 and ToN13), SDN (especially, FLIP) and generic multi control-plane (INFOCOM15,ToN17) networks.

  • Network testing: Methodologies, techniques and tools for checking control-plane correctness before deployment on production networks. Our contributions span configuration checkers for distributed protocols in traditional networks (TNSM11,ToN15b), and black-box testing of OpenFlow controllers (TASTE).

  • Routing theory: Graph-based modeling and formal analysis of distributed network protocols, notably policy-based routing ones as BGP. Our main results include the characterizations of the BGP expressive power and complexity of related routing problems (ICNP13), as well as the identification of sufficient and necessary conditions for guaranteed configuration correctness (ICNP09,INFOCOM12).

  • Measurements: Analyses of active measurements on Internet routing. We conducted large-scale measurement campaign to support key claims in our papers (see, for example, the ToN15b paper on iBGP Policies). We have also performed bias analyses of existing measurement infrastructures, including distributed platforms as RIPE Atlas (IMC13) and publicly-available datasets like RIS/Routeviews BGP ones (Networking14).

Selected Publications

Hereafter, a list of the most important articles that I have co-authored (with several great collaborators!). A complete list is available on my Publications page.

  • O. Tilmans, T. Buhler, I. Poese, S. Vissicchio, L. Vanbever. Stroboscope: Declarative Network Monitoring on a Budget. In Proc. NSDI, 2018. (paper) (talk) (Web site)

  • N. Gvozdiev, S. Vissicchio, B. Karp, M. Handley. Low-Latency Routing on Mesh-Like Backbones. In Proc. HotNets, 2017. (paper)

  • T. Holterbach, S. Vissicchio, A. Dainotti, L. Vanbever. SWIFT: Predictive Fast Reroute. In Proc. SIGCOMM, 2017. (paper) (talk) (Web site)

  • S. Vissicchio, L. Cittadini. FLIP the (Flow) Table: Fast LIghtweight Policy-preserving SDN Updates. In Proc. INFOCOM, 2016. (paper) (talk)
    Selected as INFOCOM 2016 Best Paper Award Runner-up

  • S. Vissicchio, O. Tilmans, L. Vanbever, J. Rexford. Central Control over Distributed Routing. In Proc. SIGCOMM 2015. (paper) (talk) (Web site)
    Selected as SIGCOMM 2015 Best Paper, awarded with the IRTF Applied Network Research Prize 2016

  • R. Hartert, S. Vissicchio, P. Schaus, O. Bonaventure, C. Filsfils, T. Telkamp, P. Francois. A Declarative and Expressive Approach to Control Forwarding Paths in Carrier-Grade Networks. In Proc. SIGCOMM 2015. (paper) (talk) (Web site)

  • S. Vissicchio, L. Cittadini, G. G. Xie, O. Bonaventure, L. Vanbever. On the Co-Existence of Distributed and Centralized Routing Control-Planes. In Proc. INFOCOM, 2015. (paper) (talk)

  • S. Vissicchio, L. Vanbever, O. Bonaventure. Opportunities and Research Challenges of Hybrid Software Defined Networks. ACM SIGCOMM Computer Communications Review. 44(2):70- 75. April 2014. (paper)

  • M. Chiesa, L. Cittadini, G. Di Battista, L. Vanbever, S. Vissicchio. Using Routers to Build Logic Circuits: How Powerful is BGP? In Proc. ICNP, 2013. (paper)
    Selected as ICNP 2013 Best Paper

  • S. Vissicchio, L. Vanbever, C. Pelsser, L. Cittadini, P. Francois, O. Bonaventure. Improving Network Agility with Seamless BGP Reconfigurations. IEEE/ACM Transactions on Networking. 21(3):990-1002. June 2013. (paper)
    Awarded with the IRTF Applied Network Research Prize 2013

  • C. Pelsser, L. Cittadini, S. Vissicchio, R. Bush. From Paris to Tokyo: On the Suitability of ping to Measure Latency. In Proc. IMC, 2013. (paper)

  • L. Vanbever, S. Vissicchio, C. Pelsser, P. Francois, O. Bonaventure. Seamless Network-Wide IGP Migrations. In Proc. SIGCOMM, 2011. (paper)

  • L. Cittadini, G. Di Battista, M. Rimondini, S. Vissicchio. Wheel + Ring = Reel: the Impact of Route Filtering on the Stability of Policy Routing. In Proc. ICNP, 2009. (paper)


Hereafter, you can find pointers to the code produced with my collaborators and myself during research projects in which I have participated.

  • REPETITA: a software framework for repeatable experiments on traffic engineering (TE) algorithms. It includes more than 250 real topologies, the implementation of state of the art TE algorithms (with IGP weight optimization and segment routing), and easy-to-run analyses

  • SWIFT inference algorithm and VM: predictively rerouting traffic to drastically speed up reaction to remote inter-domain failures

  • Fibbing controller: profitably using distributed routing protocols for centralized control

  • DEFO optimization module: optimizing forwarding paths with Constraint Programming

  • FLIP algorithm: computing fast, low-memory and policy-preserving updates of OpenFlow networks by combining rule replacements and tag-and-match operations

  • Hybrid SDN update algorithms: guaranteeing usage of either initial or final paths throughout the update of traditional, SDN and mixed networks

  • SCMon prototype: monitoring an entire network from a single box with Segment Routing