Research
My research interests are in routing and distributed systems. More specifically in improving the scalability and resilience of intra-domain routing. This includes transient-free iBGP (internal BGP) route propagation, as well as IGP policy routing and SDN. Here are some of the projects / publications I was / am involved.
LOUP
Under misconfiguration or topology changes, iBGP with route reflectors exhibits a variety of ills, including routing instability, transient loops, and routing failures. In this work we considered the intra-domain route dissemination problem from first principles, and showed that these pathologies are not fundamental–rather, they are artifacts of iBGP. We proposed the Simple Ordered Update Protocol (SOUP) and Link-Ordered Update Protocol (LOUP), clean-slate dissemination protocols for external routes that do not create transient loops, make stable route choices in the presence of failures, and achieve policy-compliant routing without any configuration. We proved SOUP cannot loop, and demonstrated both protocols’ scalability and correctness in simulation and through measurements of a Quagga-based implementation. The website for the project is http://nrg.cs.ucl.ac.uk/loup/index.html.
Publications:
Nikola Gvozdiev, Brad Karp, and Mark Handley. Loup: who’s afraid of the big bad loop? In the 11th ACM Workshop on Hot Topics in Networks (HotNets ‘12), pages 19–24. ACM, 2012.
Nikola Gvozdiev, Brad Karp, Mark Handley, et al. Loup: The principles and practice of intra-domain route dissemination. In the 10th USENIX Symposium on Networked Systems Design and Implementation (NSDI ‘13), pages 413–426, 2013.
FUBAR
FUBAR is a system that reduces congestion and maximizes the utility of the entire network by installing new routes and changing the traffic load on existing ones. FUBAR works offline to periodically adjust the distribution of traffic on paths. It requires neither changes to end hosts nor precise prior knowledge of the traffic matrix. We demonstrate that even in the presence of traffic from all network devices to all other devices, FUBAR can optimize a real-world core-level network in a matter of minutes. The code that was used to produce the results is here.
Publications:
Nikola Gvozdiev, Brad Karp, and Mark Handley. Fubar: Flow utility based routing. In the 13th ACM Workshop on Hot Topics in Networks (HotNets ‘14), page 12. ACM, 2014.