Ufuk Usubütün

Computer Networks

Protocols

Cross-Layer Analysis

Greetings from New York City! This is Ufuk! And here’s my résumé

In my research, I start with real-world networking systems and protocols, then build the models that make sense of them. In doing so, I take a cross-layer approach. I have extensive experience interpreting standards in different realms (e.g. IETF, 3GPP, Open-RAN, Ultra Ethernet) and protocol implementations (e.g. Linux TCP). I conduct my experiments on networking testbeds (e.g. Cloudlab, Fabric) and I am experienced with analytical modeling of queuing systems. I am also experienced with network optimization.

Since the start of my PhD at NYU in 2020, I interned with Nokia Bell Labs (on routing optimization), with AT&T Labs Research (on 5G RRC Layer Modeling) and Marvell Semiconductors (on Ultra Ethernet Transport Protocols). I am also still actively involved with AT&T Labs Research as a research collaborator.

The publications page also contains pre-prints and presentation slides.

news

Jul 30, 2024	Our joint paper with AT&T, Designing Reliable Virtualized Radio Access Networks is accepted for presentation at the IEEE GLOBECOM 2024 Conference!
Apr 8, 2024	I was awarded *The Dante Youla Award for Graduate Research Excellence* by the NYU Tandon ECE department for being the student who has made the most significant research contribution among all ECE graduate students in the past year!
Aug 4, 2023	Our joint paper with Nokia Bell Labs, Oblivious Routing Using Learning Methods is accepted for presentation at the IEEE GLOBECOM 2023 Conference!
Jun 5, 2023	Our paper Do Switches Still Need to Deliver Packets in Sequence won the BEST PAPER AWARD at the IEEE HPSR Conference!

selected publications

2023

Do Switches Still Need to Deliver Packets in Sequence? - BEST PAPER AWARD

Ufuk Usubütün, Fraida Fund, and Shivendra Panwar

In HPSR 2023 - IEEE 24th International Conference on High Performance Switching and Routing, 2023

Abs HTML PDF Code Slides

Internet switches become harder and costlier to build for higher line rates and switch capacities. In-sequence delivery of packets has traditionally been a constraint on switch designs because TCP loss detection was considered vulnerable to out-of-sequence arrivals. For this reason, extremely efficient and simple designs, such as the Load Balanced Birkhoff-von Neumann Switch, were considered impractical. However, we reevaluate this constraint considering modern TCP implementations with loss detection algorithms like Recent Acknowledgment (RACK) that are more resilient to out-of-order arrivals. In a set of testbed experiments representative of wide area core networks, we evaluated the performance of TCP flows traversing a load balanced switch that reorders some packets within a flow. We show that widely deployed and standard TCP implementations of the last decade achieve similar performance when traversing a load balanced switch as they do when there is no reordering. Furthermore, we also verified that an increase in the line rate leads to favorable conditions for time based loss detection methods, such as the one used in RACK. Our results, if further validated, suggest that switch designs that were previously thought to be unsuitable can potentially be utilized, thanks to the relaxation of the in-sequence delivery constraint.