Alexander Krentsel
Alexander Krentsel has been at Google since 2019, and has been a Systems Research Engineer in the Systems Research Group since 2021. He is concurrently a PhD student at UC Berkeley, advised by Scott Shenker and Sylvia Ratnasamy. His research at Google is broadly in network architecture designs and increasing network availability/resiliency.
Find more info at https://people.eecs.berkeley.edu/~akrentsel/.
Authored Publications
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The Case for Validating Inputs in Software-Defined WANs
Rishabh Iyer
Isaac Keslassy
Sylvia Ratnasamy
The 23rd ACM Workshop on Hot Topics in Networks (HOTNETS ’24), ACM, Irvine, CA (2024) (to appear)
Preview abstract
We highlight a problem that the networking community has
largely overlooked: ensuring that the inputs to network controllers in software-
defined WANs are accurate. We we show that “incorrect” inputs are a common
cause of major outages in practice and propose new directions to address these.
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A Decentralized SDN Architecture for the WAN
Nitika Saran
Ashok Narayanan
Sylvia Ratnasamy
Ankit Singla
Hakim Weatherspoon
2024 ACM Special Interest Group on Data Communication (SIGCOMM) (2024)
Preview abstract
Motivated by our experiences operating a global WAN, we argue that SDN’s reliance on infrastructure external to the data plane has significantly complicated the challenge of maintaining high availability. We propose a new decentralized SDN (dSDN) architecture in which SDN control logic instead runs within routers, eliminating the control plane’s reliance on external infrastructure and restoring fate sharing between control and data planes.
We present dSDN as a simpler approach to realizing the benefits of SDN in the WAN. Despite its much simpler design, we show that dSDN is practical from an implementation viewpoint, and outperforms centralized SDN in terms of routing convergence and SLO impact.
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