Philip Brighten Godfrey | |
Ph.D., Computer Science, UC Berkeley, May 2009.
Office: 3211 Siebel Center I am a professor in the Siebel School of Computing and Data Science and the CSL at the University of Illinois at Urbana-Champaign. I was co-founder and CTO of startup Veriflow, which pioneered network verification technology and was acquired in 2019 by VMware (now Broadcom), where I served as technical director through 2025. Before joining UIUC, I was a Ph.D. student at UC Berkeley, advised by Ion Stoica, and a visiting researcher at Intel Labs Berkeley. Ph.D. applicants: I encourage you to apply to UIUC CS for the 2025 admission season. Our group is always interested in strong applicants in the broad area of networked systems. The type of work in our group spans building networked systems, applications of ML to networked systems, and algorithms and optimization for networks. Read more about our group's current research thrusts below. Apply to our PhD program and list my name as one of the faculty you are interested to work with. UIUC has a fantastic group of faculty in the Systems and Networking space and I encourage you to explore who is the best fit for you. Undergraduate research: Drop me an email to let me know you're interested, and be sure to fill out this interest form (you'll need to be logged in with your Illinois Google account). Research | Papers | News | Group | Teaching | Service |
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Research
I enjoy building networked systems that address practical problems, with strong architectural and theoretical foundations. You can check out my complete list of papers. My group is currently working in several main areas:
- Low latency networking: We're leading Project Agora, a $7.1M NSF Breaking Low project to develop deployable low-latency wireless networking, and demonstrate its use for XR-based medical collaboration. Our other projects include the Speed of Light Internet, DChannel, HVCs, and WTSN for low latency WiFi.
- Machine learning for systems: Our group is part of the LDOS NSF Expeditions In Computing project, which is building a clean-slate Learning Directed Operating System. We've also worked on online learning for congestion control (Aurora and PCC), deep learning as an adversary, and performance diagnosis (Murphy).
- Service layer networking to optimize, observe, and secure communication between microservices. See news article: CS-led team pioneers improvement of microservice-based applications and our HotNets 2021 paper which put forth a vision of Service meshes as a new network layer. We've built Service Layer Traffic Engineering (SLATE) (in HotNets 2024 and to appear in NSDI 2026), TraceWeaver: Distributed Request Tracing for Microservices Without Application Modification, and expressive policies for microservices.
- Network verification and formal methods: Our group pioneered network verification, specifically building the first data plane verifier applied to a real network (
Anteater ) and the first real-time data plane verifier (VeriFlow ), which led to our startup Veriflow, now part of VMware. We've worked on customizable consistency properties (CCG ), fast configuration verification (Plankton), verifying self-driving infrastructure, verifying systems of multiple microservice controllers (Kivi ), expressive policies for microservices (HotNets 2023 andSafeTree in OOPSLA 2025 ), and automated reasoning for network architectures (HotNets 2024 ).
Other areas of work recently and in the past include:
- Data center network topology, specifically the Jellyfish expander graph (
NSDI 2012 ,NSDI 2014 ), measuring and understanding throughput (SC 2016 ), spineless data centers (HotNets 2020 ), Starfish (to appear in NSDI 2026) - Network diagnosis, including including network fault localization (Flock) and diagnosing performance problems in distributed apps (Murphy)
- Compact routing and fast shortest path algorithms in social networks
- Flexible Internet architectures
- Peer-to-peer systems
Recent News
2026:
- Congratulations to group alumnus Sangeetha Abdu Jyothi, winner of the 2026 ACM SIGMETRICS Rising Star Award!
- News article about Project Agora: Illinois Leads $7.1M NSF Project Advancing Low-Latency Networking for XR-Based Medical Collaboration
2025:
- NSF has awarded Project Agora, a $7.1 million project that will develop deployable low-latency wireless networking, and demonstrate its use for medical collaboration. The project is led by myself (PI), Sarita Adve and Christine Zhang (co-PIs), with members from the UIUC Siebel School for Computing and Data Science, the Carle Illinois College of Medicine, Peraton Labs, MediView, T-Mobile, Qualcomm, and Cisco. Agora is one of just three projects awarded in the NSF Breaking Low program.
- Here's my unhinged rant on the paper reviewing process used by the networking community, focused on the problem that it can take years to publish a paper, even after the work is essentially done. I was also a panelist in the reviewing discussion at the SIGCOMM'25 Community Session (video) in Coimbra in September.
- CellReplay, led by William Sentosa, won the Community Award for best paper with open code and data at NSDI 2025! You can use CellReplay now for accurate record-and-replay emulation of cellular networks.
- Our work on low latency networking and its application to XR has new papers out: an investigation of whether WTSN is the missing piece for low latency Wi-Fi (HotMobile'25) led by Milind Kumar V; and XRgo and RemoteVIO, both in MMsys 2025 and in collaboration with Sarita Adve's group, which offload rendering and VIO components of the XR stack, respectively.
- My Spring 2025 course CS 435 Cloud Networking is on the List of Teachers Ranked as Excellent by Their Students!
- Looking forward to serving as PC Co-Chair of HotNets 2025 with Barath Raghavan!
- Congrats to undergraduate researcher Aditya Prerepa on his graduation! Aditya co-led the SLATE project, which was presented in EnvoyCon'23 and HotNets'24, and will appear in NSDI 2026.
- Honored to give the invited keynote talk, Understanding and Improving Robustness of Networked Systems with Machine Learning, at NetDev 0x19 on March 11 in Zagreb, Croatia! The talk video is now online. I was also honored to deliver this talk at the Queen Mary University of London Next Generation Networking Webinar Series in March.
- Invited talk in the Qualcomm Academic Lecture Series on "Democratizing Low Latency: A Grand Challenge for Networking", October 2025
2024:
- Enjoyed giving an invited talk, "Improving Robustness of Networked Systems With Machine Learning", at the Google AIOps Workshop in November 2024
- Two papers in HotNets this year, in the areas of microservices and formal methods for networks respectively: Opportunities and Challenges in Service Layer Traffic Engineering, led by Gangmuk Lim and Aditya Prerepa, and Lightweight Automated Reasoning for Network Architectures led by Rahul Bothra
- Lots happening at SIGCOMM this year in addition to papers. I gave the keynote talk "The Networks Above the Network: Opportunities for Formal Methods in The World of Cloud Native Computing" at the ACM SIGCOMM Workshop on Formal Methods Aided Network Operation (FMANO) in August 2024, and was also a panelist in the SIGCOMM reviewing panel.
- Two papers on microservices this summer: Kivi in USENIX ATC, led by Bingzhe Liu, is the first verifier for interactions among microservice controllers, and TraceWeaver in ACM SIGCOMM, led by Sachin Ashok and with our collaborators at IBM, reconstructs distributed traces of requests flowing across microservices, without modifying applications to propagate request context.
- Excited to kick off the Learning Directed Operating System (LDOS) project, a 5-year, $12 million NSF Expedition project that will build an intelligent and self-adaptive operating system. Gang Wang and I are co-PIs at UIUC, and the project is led by PI Aditya Akella.
- Invited talk "Expanding the scope of network verification to microservices" at the Bellairs Network Verification Workshop, April 2024
- Our $1.1 million NSF project on networking for microservices kicked off recently, with co-PIs Radhika Mittal and R. Srikant -- see the news article CS-led team pioneers improvement of microservice-based applications
2023:
- Congratulations to Bingzhe Liu on her Ph.D. dissertation defense!
- Excited to share two papers in HotNets 2023 from different thrusts of our group's work, on low latency networking for interactive applications, and expressive policies for microservice communication
- Our group has two upcoming talks at KubeCon 2023 in Chicago: Bingzhe Liu and Gangmuk Lim on verifying Kubernetes controllers, and Gangmuk Lim and Aditya Prerepa on service layer traffic engineering with SLATE.
- My course CS 538 in Spring 2023 is on the List of Teachers Ranked as Excellent by Their Students
- Congratulations to Vipul Harsh on his Ph.D. dissertation defense!
- Check out VMware's blog on commercial impact of Murphy, which appeared in SIGCOMM'23
- I've joined the ACM SIGCOMM Steering Committee for a three-year term, 2023 - 2026.
- Enjoyed speaking on cISP at the Harvard Systems + Theory Seminar in February
Teaching
- CS 435: Cloud Networking (Spring 2026, Spring 2025, Spring 2024, Fall 2021, Fall 2022)
- CS 591 UP: Computing Startup Seminar (Fall 2025)
- CS 538: Advanced Computer Networks (Spring 2023, Spring 2021, Spring 2019, Spring 2018, Spring 2017, Fall 2013, Fall 2012, Fall 2011)
- CS 498: Cloud Networking (Fall 2020, Fall 2019, Fall 2018)
Research Group
Current members
- Shehab Sarar Ahmed (Ph.D.)
- Sachin Ashok (Ph.D., co-advised with Radhika Mittal)
- Rahul Bothra (Ph.D.)
- Gangmuk Lim (Ph.D.)
- Gerard Matthew (Ph.D.)
- Aditya Prerepa (Undergraduate)
- William Sentosa (Ph.D.)
- Milind Kumar Vaddiraju (Ph.D.)
- Talha Waheed (Ph.D., co-advised with Radhika Mittal)
- Wanyu Zhao
Ph.D. alumni
- Bingzhe Liu (2024, now Research Scientist at Meta)
- Vipul Harsh (2024, now postdoc at Conviva)
- Tong Meng (2021, now at ByteDance)
- Ali Kheradmand (2021, co-advised with Grigore Rosu, now at Google)
- Sangeetha Abdu Jyothi (2019, now assistant professor at UC Irvine)
- Mo Dong (2017, now co-founder at Celer Network)
- Soudeh Ghorbani (2016, now assistant professor at Johns Hopkins)
- Qingxi Li (2016, now at Google)
- Ankit Singla (2015, now assistant professor at ETH Zurich)
- Ashish Vulimiri (2015, co-advised with Gul Agha, now at Samsung Research)
- Chi-Yao Hong (2014, co-advised with Matt Caesar, now at Google)
- Rachit Agarwal (2013, co-advised with Matt Caesar, now professor at Cornell)
Postdoc alumni
- Anduo Wang (Postdoc 2013-2015, with Matthew Caesar, now assistant professor at Temple University)
M.S. alumni
- Talal Touseef (2024)
- Aditi Partap (2021, co-advised with Radhika Mittal, now Ph.D. student at Stanford)
- Nathan Jay (2019)
- Fatima Tariq (2019)
- Fan Yang (2015)
- Kyle Jao (2014)
- Abhishek Sharma (2013)
- Sam Mussmann (2012)
Service
- NINeS 2027 program committee
- ACM HotNets 2025 PC co-chair
- ACM SIGCOMM 2025 program committee
- USENIX NSDI 2025 program committee
- ACM SIGCOMM Steering Committee, 2023-26
- USENIX NSDI 2024 program committee
- SIGCOMM 2022 program committee co-chair
- USENIX NSDI 2022 program committee
- HotNets 2021 program committee
- CoNEXT 2020 program committee
- SIGCOMM 2018 program committee
- SIGMETRICS 2017 program committee
- HotNets 2017 program committee
- SIGCOMM 2017 Workshop on VR/AR Network program committee
- SOSR 2016 PC co-chair
- SIGCOMM 2015 program committee
- Dagstuhl Seminar on Formal Methods and Networks (2015), co-organizer
- HotNets 2014 PC co-chair
Random
- Short biography
- Photo
- Writing on You Infinite Snake (blog) and elsewhere
- Network verification: predicting the future of complex networks (Network World, November 27, 2017)
- Why Tech Leaders Should Always Keep an Eye on Academia
- Attractive scientific plots with gnuplot
- Google Frequency Plotter
- Programming Language Wars: The Movie
- What happened to the Internet on Friday
- Computer Science Research Trends
- Graphing English
- Outreach activities
- Advice on obtaining grants
- Repository of Availability Traces
Traces from measurement studies of PlanetLab, web sites, corporate PCs, Skype superpeers, and DNS servers packaged in a single compact format. - Great talks on education: Clifford Stoll, Ken Robinson
