Nanosecond Precision Time Synchronization for Optical Data Center Networks
Yiming Lei, Jialong Li, Zhengqing Liu, Raj Joshi, Yiting Xia

TL;DR
This paper introduces NOS, a nanosecond-precision synchronization method for optical data center networks, enabling accurate timing essential for routing and improving network performance.
Contribution
It presents the first general nanosecond-precision synchronization solution for optical DCNs, including clock tree construction, drift prediction, and protocol adaptations.
Findings
Achieves 28ns synchronization accuracy in a 192-ToR network
Builds clock propagation trees on reconfigurable optical circuits
Predicts drift to minimize synchronization errors
Abstract
Optical data center networks (DCNs) are renovating the infrastructure design for the cloud in the post Moore's law era. The fact that optical DCNs rely on optical circuits of microsecond-scale durations makes nanosecond-precision time synchronization essential for the correct functioning of routing on the network fabric. However, current studies on optical DCNs neglect the fundamental need for accurate time synchronization. In this paper, we bridge the gap by developing Nanosecond Optical Synchronization (NOS), the first nanosecond-precision synchronization solution for optical DCNs general to various optical hardware. NOS builds clock propagation trees on top of the dynamically reconfigured circuits in optical DCNs, allowing switches to seek better sync parents throughout time. It predicts drifts in the tree-building process, which enables minimization of sync errors. We also tailor…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsNetwork Time Synchronization Technologies · Photonic and Optical Devices · Quantum optics and atomic interactions
