Journal ArticleDOI
ReversePTP: A clock synchronization scheme for software-defined networks
Tal Mizrahi,Yoram Moses +1 more
TLDR
In REVERSEPTP, a clock synchronization scheme for software-defined networks SDNs is introduced, which is based on the Precision Time Protocol PTP, but is conceptually reversed; all nodes switches in the network distribute timing information to a single software-based central node the SDN controller, which tracks the state of all the clocks in a network.Abstract:
We introduce REVERSEPTP, a clock synchronization scheme for software-defined networks SDNs. REVERSEPTPi¾?is based on the Precision Time Protocol PTP, but is conceptually reversed; in REVERSEPTP, all nodes switches in the network distribute timing information to a single software-based central node the SDN controller, which tracks the state of all the clocks in the network. Hence, all computations and bookkeeping are performed by the central node, whereas the 'dumb' switches are only required to periodically send it their current time. In accordance with the SDN paradigm, the 'brain' is implemented in software, making REVERSEPTP flexible and programmable from an SDN programmer's perspective. We present the REVERSEPTPi¾?architecture and discuss how it can be used in typical SDN architectures. Our experimental evaluation of a network with 34 REVERSEPTP-enabled nodes demonstrates the effectiveness and scalability of using REVERSEPTP. Copyright © 2016 John Wiley & Sons, Ltd.read more
Citations
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Journal ArticleDOI
Survey of Consistent Software-Defined Network Updates
TL;DR: This paper identifies the different desirable consistency properties that should be provided throughout a network update, the algorithmic techniques which are needed to meet these consistency properties, and the implications on the speed and costs at which updates can be performed.
Journal ArticleDOI
An Enhanced Reconfiguration for Deterministic Transmission in Time-Triggered Networks
Zonghui Li,Hai Wan,Zaiyu Pang,Qiubo Chen,Yangdong Deng,Xibin Zhao,Yue Gao,Xiaoyu Song,Ming Gu +8 more
TL;DR: This paper presents a reconfiguration mechanism that significantly reduces the number of loss frames and achieves zero loss in almost all cases and evaluates the proposed mechanism in two real industrial network topologies.
Journal ArticleDOI
IEEE 1588 for Clock Synchronization in Industrial IoT and Related Applications: A Review on Contributing Technologies, Protocols and Enhancement Methodologies
TL;DR: This study has compared the well-known synchronization techniques and concluded that the PTP is the most appropriate answer to robust clock synchronization though challenges are there that requires thoughtful efforts and modification in the current version.
Journal ArticleDOI
Estimators for Time Synchronization—Survey, Analysis, and Outlook
TL;DR: The intention behind this is to identify estimation methods that are particularly worth considering, as these already achieve good results in the wireless area but have not yet been examined in the wired area (and vice versa).
Journal ArticleDOI
WhiteRabbit: Scalable Software-Defined Network Data-Plane Verification Method Through Time Scheduling
TL;DR: WhiteRabbit is an approach to verify the consistency of the forwarding state by gathering real-time network statistics gathering from switches with accurate time scheduling and mitigates the effect on the verification accuracy from the impact of the switch performance, such as scheduling error.
References
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OpenFlow: enabling innovation in campus networks
Nick McKeown,Thomas Anderson,Hari Balakrishnan,Guru Parulkar,Larry L. Peterson,Jennifer Rexford,Scott Shenker,Jonathan S. Turner +7 more
TL;DR: This whitepaper proposes OpenFlow: a way for researchers to run experimental protocols in the networks they use every day, based on an Ethernet switch, with an internal flow-table, and a standardized interface to add and remove flow entries.
Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems
Kang B. Lee,J Eldson +1 more
TL;DR: A protocol is provided in this standard that enables precise synchronization of clocks in measurement and control systems implemented with technologies such as network communication, local computing, and distributed objects.
Proceedings ArticleDOI
IEEE 1588 standard for a precision clock synchronization protocol for networked measurement and control systems
J C. Eidson,Kang B. Lee +1 more
TL;DR: This paper discusses the major features and design objectives of the IEEE-1588 standard, designed to serve the clock synchronization needs of industrial systems, and recent performance results of prototype implementations of this standard in an Ethernet environment are presented.
Network Time Protocol Version 4: Protocol and Algorithms Specification
TL;DR: NTP version 4 (NTPv4), which is backwards compatible with NTP version 3 (N TPv3), described in RFC 1305, as well as previous versions of the protocol, are described.
Journal ArticleDOI
Spanner: Google’s Globally Distributed Database
James C. Corbett,Jeffrey Dean,Michael James Boyer Epstein,Andrew Fikes,Christopher Frost,J. J. Furman,Sanjay Ghemawat,Andrey Gubarev,Christopher Heiser,Peter Hochschild,Wilson C. Hsieh,Sebastian Kanthak,Eugene Kogan,Hongyi Li,Alexander Lloyd,Sergey Melnik,David Mwaura,David Nagle,Sean Quinlan,Rajesh Rao,Lindsay Rolig,Yasushi Saito,Michal Piotr Szymaniak,Chris Jorgen Taylor,Ruth Wang,Dale Woodford +25 more
TL;DR: Spanner as mentioned in this paper is Google's scalable, multiversion, globally distributed, and synchronously replicated database, which is the first system to distribute data at global scale and support externally-consistent distributed transactions.