The document summarizes precision time synchronization techniques. It begins with an overview of time synchronization and its applications in fields like industrial automation, stock trading, and cloud computing. It then provides details on IEEE 1588, including its objectives to achieve sub-microsecond synchronization across networked devices and support for heterogeneous clock systems. The document discusses PTP communication ports, roles, and the Best Master Clock Algorithm for determining roles. It also outlines PTP message types and how hardware-assisted time stamping increases accuracy. Lastly, it promotes participation in the 2012 International Symposium on Precision Clock Synchronization for Measurement, Control and Communication.
Getting clocks to agree on the time is tricky. Getting them to agree on the time better than 100 nanoseconds is even trickier.
In this talk I will provide an introduction to the basic principles of the Precision Time Protocol (PTP) and how it can be used to precisely synchronize computers over a LAN.
http://www.nycbug.org/index.cgi?action=view&id=10361
Getting clocks to agree on the time is tricky. Getting them to agree on the time better than 100 nanoseconds is even trickier.
In this talk I will provide an introduction to the basic principles of the Precision Time Protocol (PTP) and how it can be used to precisely synchronize computers over a LAN.
http://www.nycbug.org/index.cgi?action=view&id=10361
Stories from the PTP Battlefront - Corvil at STAC LondonCorvil
STAC London, October 2016: James Wylie, Director of Technical Services, was uniquely situated to share his experiences of the good, bad, and ugly of real PTP deployments. In his talk, “Stories from the PTP Battlefront,” James addressed a number of the problems that can accompany sub-microsecond accuracy in real-life deployments, and how they were diagnosed and solved.
The ability to synchronise security equipment is becoming ever more important. This is not only for ensuring consistency, but also for evidential purposes.
In this slide deck we cover:
- Understanding the relationship between OFDM theory and practice
- Starting from a Matlab script through to automatic HDL code/bitstream generation
- Introduction to Nutaq’s PicoSDR hardware and software
- Creating host applications to exchange data with the PicoSDR in real-time
ContikiMAC : Radio Duty Cycling ProtocolSalah Amean
Several MAC duty-cycle protocols have been proposed during the last decade to
address specific WSNs requirements and constraints such as a
low energy consumption linked to battery operated nodes
Radio Duty-Cycle (RDC) MAC protocols try to reduce the energy consumption by allowing a node to keep its radio-transceiver off most of the time.
This allow a node to avoid to keep the radio on unnecessarily, i.e when not involved in any transmission
Idle listening is used to solve such problem in which RDC MAC forces node to switch its transceiver between short active(listen) periods and long inactive (sleep) periods
. This presentation introduces a very important concept in wireless sensor network, particularly in handling transmission and reception of packets in very limited resources channel.
Machine Learning Based Session Drop Prediction in LTE Networks and its SON As...Ericsson
Abnormal bearer session release (i.e. bearer session drop) in cellular telecommunication networks may seriously impact the quality of experience of mobile users. The latest mobile technologies enable high granularity real-time reporting of all conditions of individual sessions, which gives rise to use data analytics methods to process and monetize this data for network optimization. One such example for analytics is Machine Learning (ML) to predict session drops well before the end of session.
Performance Evaluation of GTP-U and SRv6 Stateless TranslationChunghan Lee
The GPRS Tunneling Protocol User Plane (GTP-U) has long been deployed for GSM, UMTS and 4G LTE. Now for 5G, IPv6 Segment Routing (SRv6) has been proposed as an alternative user plane protocol to GTP-U in both 3GPP and IETF. SRv6 based on source routing has many advantages: stateless traffic steering, network programming and so on. Despite the advantages, it is hard to expect to replace GTP-U by SRv6 all at once, even in a 5G deployment because of a lot of dependencies between 3GPP nodes. Therefore, stateless translation and co- existence with GTP-U have been proposed in IETF. However there are no suitable measurement platform and performance evaluation results between GTP-U and SRv6. In particular, it is hard to measure latency on commercial traffic generators when a receiving packet type is different from a sending packet type. In this paper, we focus on the performance evaluation between GTP-U and SRv6 stateless translation. We designed an SRv6 measurement platform using a programmable switch, and measured GTP-U and SRv6 functions with pre-defined scenarios on a local environment. Well-known performance metrics, such as throughput and packets per second (PPS), are measured by the traffic generator while the latency at the functions was measured using telemetry on our SRv6 platform. In our evaluation, we cannot find the abrupt performance drop of well-known metrics at SRv6 stateless translation. Moreover, the latency of SRv6 stateless translation is similar to GTP-U and their performance degradation is negligible. Through the evaluation results, it is obvious that the SRv6 stateless translation is acceptable to the 5G user plane.
Small Cell Timing and Sync Presentation SCA 2013David Chambers
Presentation given at Small Cells Americas December 2013 explaining and positioning timing and sychronisation requirements and solutions for small cells. This highlights the need for Phase sychronisation for more advanced LTE features, which is technically demanding. The alternative synchronisation schemes are discussed, concluding in a range of recommended solutions.
Stories from the PTP Battlefront - Corvil at STAC LondonCorvil
STAC London, October 2016: James Wylie, Director of Technical Services, was uniquely situated to share his experiences of the good, bad, and ugly of real PTP deployments. In his talk, “Stories from the PTP Battlefront,” James addressed a number of the problems that can accompany sub-microsecond accuracy in real-life deployments, and how they were diagnosed and solved.
The ability to synchronise security equipment is becoming ever more important. This is not only for ensuring consistency, but also for evidential purposes.
In this slide deck we cover:
- Understanding the relationship between OFDM theory and practice
- Starting from a Matlab script through to automatic HDL code/bitstream generation
- Introduction to Nutaq’s PicoSDR hardware and software
- Creating host applications to exchange data with the PicoSDR in real-time
ContikiMAC : Radio Duty Cycling ProtocolSalah Amean
Several MAC duty-cycle protocols have been proposed during the last decade to
address specific WSNs requirements and constraints such as a
low energy consumption linked to battery operated nodes
Radio Duty-Cycle (RDC) MAC protocols try to reduce the energy consumption by allowing a node to keep its radio-transceiver off most of the time.
This allow a node to avoid to keep the radio on unnecessarily, i.e when not involved in any transmission
Idle listening is used to solve such problem in which RDC MAC forces node to switch its transceiver between short active(listen) periods and long inactive (sleep) periods
. This presentation introduces a very important concept in wireless sensor network, particularly in handling transmission and reception of packets in very limited resources channel.
Machine Learning Based Session Drop Prediction in LTE Networks and its SON As...Ericsson
Abnormal bearer session release (i.e. bearer session drop) in cellular telecommunication networks may seriously impact the quality of experience of mobile users. The latest mobile technologies enable high granularity real-time reporting of all conditions of individual sessions, which gives rise to use data analytics methods to process and monetize this data for network optimization. One such example for analytics is Machine Learning (ML) to predict session drops well before the end of session.
Performance Evaluation of GTP-U and SRv6 Stateless TranslationChunghan Lee
The GPRS Tunneling Protocol User Plane (GTP-U) has long been deployed for GSM, UMTS and 4G LTE. Now for 5G, IPv6 Segment Routing (SRv6) has been proposed as an alternative user plane protocol to GTP-U in both 3GPP and IETF. SRv6 based on source routing has many advantages: stateless traffic steering, network programming and so on. Despite the advantages, it is hard to expect to replace GTP-U by SRv6 all at once, even in a 5G deployment because of a lot of dependencies between 3GPP nodes. Therefore, stateless translation and co- existence with GTP-U have been proposed in IETF. However there are no suitable measurement platform and performance evaluation results between GTP-U and SRv6. In particular, it is hard to measure latency on commercial traffic generators when a receiving packet type is different from a sending packet type. In this paper, we focus on the performance evaluation between GTP-U and SRv6 stateless translation. We designed an SRv6 measurement platform using a programmable switch, and measured GTP-U and SRv6 functions with pre-defined scenarios on a local environment. Well-known performance metrics, such as throughput and packets per second (PPS), are measured by the traffic generator while the latency at the functions was measured using telemetry on our SRv6 platform. In our evaluation, we cannot find the abrupt performance drop of well-known metrics at SRv6 stateless translation. Moreover, the latency of SRv6 stateless translation is similar to GTP-U and their performance degradation is negligible. Through the evaluation results, it is obvious that the SRv6 stateless translation is acceptable to the 5G user plane.
Small Cell Timing and Sync Presentation SCA 2013David Chambers
Presentation given at Small Cells Americas December 2013 explaining and positioning timing and sychronisation requirements and solutions for small cells. This highlights the need for Phase sychronisation for more advanced LTE features, which is technically demanding. The alternative synchronisation schemes are discussed, concluding in a range of recommended solutions.
Telecordia NIST/WSTS Workshop: Mobile Backhaul SynchronizationADVA
Check out the Mobile Backhaul Synchronization slides that Gil Biran will be presenting at this week's Telecordia NIST/WSTS workshop in San Jose, California
Random broadcast based distributed consensus clock synchronization for mobile...LogicMindtech Nologies
NS2 Projects for M. Tech, NS2 Projects in Vijayanagar, NS2 Projects in Bangalore, M. Tech Projects in Vijayanagar, M. Tech Projects in Bangalore, NS2 IEEE projects in Bangalore, IEEE 2015 NS2 Projects, WSN and MANET Projects, WSN and MANET Projects in Bangalore, WSN and MANET Projects in Vijayangar
For enterprise software applications and related processes, highly accurate and synchronized time is a necessity. An inaccurate
computer clock can cause significant problems. A discrepancy of a minute or two could cause a significant and unacceptable margin of error, since many applications require that the time be kept accurate to the nearest second or less.
This is the third part of the mini-series of synchronization in the Topics in Digital Communication Presentations.
Timing synchronization is another key component in modem design and implementation. However, this subject, especially its practical aspects, were not covered in details in text books. The materials covered in this presentation are not really new, but discussed in the literature published over past forty years. I hope that putting them in a single slide deck can help people who want to learn more on this subject.
Fuyun Ling
Synchronization Pradeep K Sinha
Introduction
Issues in Synchronization
Clock synchronization
Event Ordering
Mutual Exclusion
Deadlock
Election algorithms
Clock Synchronization
How Computer Clocks are Implemented
Drifting of Clocks
Types of Clock Synchronization and issues in them
Clock Synchronization Algorithms
Distributed and Centralized Algorithms
Case Study
Event Ordering
Happened Before Relation
Logical Clocks Concept and Implementation
Mutual Exclusion
Centralized Approach, Distributed Approach, Token Passing Approach
Deadlocks
Election algorithms
This ppt covers different aspects about timing issues and various algorithms involved in having better sync between different systems in a distributed environment
Accurate Synchronization of EtherCAT Systems Using Distributed ClocksDesign World
Synchronization and determinism are important considerations when selecting an industrial control system and the associated fieldbus. Additionally, it’s important for field devices to have network-wide interrupts for activating outputs, capturing input data, oversampling or latching events. These are all significant facets in the overall network synchronization scheme.
This webinar on Tuesday, Oct. 23 at 2 PM EST will explain how the Distributed Clock mechanism in EtherCAT works to meet all of these functions using properties inherent to the protocol. This can be done using a standard Ethernet network adaptor, all without the overhead of IEEE 1588.
Attend this webinar to learn:
How Distributed Clocks (DCs) in EtherCAT facilitate measurement of propagation delay throughout the system and synchronize network devices to a single time value
What EtherCAT slave devices can do to facilitate temporal behavior for outputs and inputs as well as implementing data oversampling
More about some of the concepts that enable EtherCAT to have a high scan rate as well as high levels of synchronization
Discussing the Industrial Internet and the crucial role that low-power wireless sensor networks will play to gather these vast amounts of data. Describing how existing industrial wireless technologies must be extended to reach higher scales at lower costs (albeit, with lower guarantees), and the architectural approach and standards that are being developed at 6TiSCH, which encompasses work at IETF, IEEE, and industrial standard bodies.
ROLE OF DIGITAL SIMULATION IN CONFIGURING NETWORK PARAMETERSDeepak Shankar
Selecting the right Ethernet standard and configuring all the network devices in the embedded systems accurately is an extremely hard and rigorous job. The configuration depends on the topology, workloads of the connected devices, processing overhead at the switches, and the external interfaces. Network calculus, mathematical models and analytical techniques provide worst case execution time (WCET), but their probability of activity is extremely wide. This leads to overdesign which leads to higher costs, power consumption, weight, and size. Simulating the network is the best way to measure the throughput of the entire system. Digital system simulation provides better latency and throughput accuracy, but the accuracy is still limited because it does not consider the latency associated with the network OS, cybersecurity processing and scheduling. In many cases, these factors can reduce the throughput by 20-40%.
In this paper, we will present our research on modeling the entire Ethernet network, including the workloads, network flow control, scheduling, switch hardware, and software. To substantially increase the coverage and compare topologies, we have developed a set of benchmarks that provides coverage for different combination of deterministic, rate-constrained, and best effort traffic. During the presentation, we will cover the benchmarks, the list of attributes required to accurately model the traffic, nodes, switches, and the scheduler settings. We will also look at the statistics and reports required to make the configuration decision. In addition, we will discuss how the model must be constructed to study the impact of future requirements, failures, network intrusions, and security detection schemes.
Key Takeaways:
1. Learn how to efficiently use network simulation to design Ethernet systems
2. Develop a reusable benchmark and associated statistics to test different configurations
3. The role and impact of the CDT slots, guard band, send slope, idle slope, shuffle scheduling, flow control and virtual channels
XPDS13: On Paravirualizing TCP - Congestion Control on Xen VMs - Luwei Cheng,...The Linux Foundation
While datacenters are increasingly adopting VMs to provide elastic cloud services, they still rely on traditional TCP for congestion control. In this talk, I will first show that VM scheduling delays can heavily contaminate RTTs sensed by VM senders, preventing TCP from correctly learning the physical network condition. Focusing on the incast problem, which is commonly seen in large-scale distributed data processing such as MapReduce and web search, I find that the solutions that have been developed for *physical* clusters fall short in a Xen *virtual* cluster. Second, I will provide a concrete understanding of the problem, and reveal that the situations that when the sending VM is preempted versus when the receiving VM is preempted, are different. Third, I will introduce my recent attempts on paravirtualizing TCP to overcome the negative effect caused by VM scheduling delays.
Crash course on data streaming (with examples using Apache Flink)Vincenzo Gulisano
These are the slides I used for a crash course (4 hours) on data streaming. It contains both theory / research aspects as well as examples based on Apache Flink (DataStream API)
Introduction
Background
WSN Design Issues: MAC Protocols, Routing Protocols, Transport Protocols
Performance Modeling of WSNs: Performance Metrics, Basic Models, Network Models
Case Study: Simple Computation of the System Life Span
Practical Example.
Industrial Networks: the Choices for Real Time Motion ControlDesign World
Among the versions of Ethernet for real-time motion update, two are leading the industry today: EtherCAT, Ethernet/IP, and Powerlink. Each handles real-time messaging differently, and the differences affect your design choices. The leading vendors behind these networks will discuss the ways each handles real-time updates. By watching this special, free 1-hour on-demand webinar you will gain a better understanding of the key factors necessary to make the best network choice for your motion application.
Tsinghua University: Two Exemplary Applications in ChinaDataStax Academy
In this talk, we will share the experiences of applying Cassandra with two real customers in China. In the first use case, we deployed Cassandra at Sany Group, a leading company of Machinery manufacturing, to manage the sensor data generated by construction machinery. By designing a specific schema and optimizing the write process, we successfully managed over 1.5 billion historical data records and achieved the online write throughput of 10k write operations per second with 5 servers. MapReduce is also used on Cassandra for valued-added services, e.g. operations management, machine failure prediction, and abnormal behavior mining. In the second use case, Cassandra is deployed in the China Meteorological Administration to manage the Meteorological data. We design a hybrid schema to support both slice query and time window based query efficiently. Also, we explored the optimized compaction and deletion strategy for meteorological data in this case.
A Platform for Data Intensive Services Enabled by Next Generation Dynamic Opt...Tal Lavian Ph.D.
The new architecture is proposed for data intensive enabled by next generation dynamic optical networks
Offers a Lambda scheduling service over Lambda Grids
Supports both on-demand and scheduled data retrieval
Supports bulk data-transfer facilities using lambda-switched networks
Provides a generalized framework for high performance applications over next generation networks, not necessary optical end-to-end
Supports out-of-band tools for adaptive placement of data replicas
Data Science with Spark - Training at SparkSummit (East)Krishna Sankar
Slideset of the training we gave at the Spark Summit East.
Blog : https://doubleclix.wordpress.com/2015/03/25/data-science-with-spark-on-the-databricks-cloud-training-at-sparksummit-east/
Video is posted at Youtube https://www.youtube.com/watch?v=oTOgaMZkBKQ
R, Data Wrangling & Kaggle Data Science CompetitionsKrishna Sankar
Presentation for my tutorial at Big Data Tech Con http://goo.gl/ZRoFHi
This is the R version of my pycon tutorial + a few updates
It is work in progress. I will update with daily snapshot until done.
Notes about Amazon VPC, a canonical architecture and finally how to implement MongoDB replica sets. My blog http://goo.gl/0guF2 has the color pictures. And the file is at http://doubleclix.files.wordpress.com/2012/10/vpc-distilled-04.pdf. For some reason, slideshare trims the colors.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
How world-class product teams are winning in the AI era by CEO and Founder, P...
Precision Time Synchronization
1. THE HITCHHIKER’S GUIDE
TO PRECISION TIME
SYNCHRONIZATION
HPTS v14
October 24, 2011
ksankar42@gmail.com [doubleclix.wordpress.com]
2. PRECISION TIME
SYNCHRONIZATION!
The future is an obsession ... an attraction ... an invention … an invitation
3. It does not matter where the
train is going, what matters is
it’s direction and your decision
to get on …
4. “Give me a lever long enough & a fulcrum on which to
place it, & I shall move the world.”
A carchesion is a kind of swivel or universal joint.
5. •
•
–
Krishna Sankar, Lead Architect, Egnyte.com – Cloud Storage
Past Life ; Distinguished Engineer About me
Chief subordinate to Assistant to Chief of Staff to CTO to the CEO of Cisco, Focusing on Cloud
Computing & Data Clouds
– C3L Project on Storage Overlay Network Fabric for Big Data (Hadoop)
• Co-chair : DMTF Cloud Incubator
• ETSI STF (Electronic Digital Signatures), W3C, OASIS (TAB, SAML et al)
• Writing a Book on Cloud Computing
– “Building Clouds with Amazon Web Services”; Editor Michael Swaine
• Working on
– Stanford MMDS (Mining Massive Data Sets Post Graduate Certificate Course
– MS Bioinformatics - John Hopkins Advanced Biotechnology Studies(Started)
• OSCON’10 “Building a Bog data Cloud”[Link], Available now as a video [Link]
• Author : Enterprise Web 2.0 Fundamentals, Wireless LAN Security
– Written a few Java books. Don’t buy them – they are very old
• Member: Scala Expert group on STM/July 2010
• Writing code for SNIA CDMI Ref Impl – File based Object Store SPI
• Lego Robotics : Technical Judge FLL World Festivals
6. Agenda
" What
is
Time
Synchroniza5on
anyway
?
" IEEE
1588
v2
" IETF
TicToc
" ISPCS
2012
" Q&A
…
The road lies plain before me;--'tis a theme
Single and of determined bounds; …
- Wordsworth, The Prelude
6
8. What is Time Synchronization
Anyway ?
I am monarch of all I survey;
My right there is none to dispute;
From the centre all round to the sea
I am lord of the fowl and the brute
- Cowper, The Solitude Of Alexander SelKirk
9. Time Synchronization
• Different
than
Time
Distribu5on
• Across
a
set
of
machines
for
a
specific
applica5on
– The
value
proposi5on
of
providing
precision
5me
to
an
applica5on
is
enormous…
– …and
has
the
poten5al
to
change
the
fundamental
characteris5cs
of
applica5ons
• Slowly
finding
it’s
way
into
routers
&
blade
server
fabrics
10. Applications
• Ocean
observatory
networks
• Digital
substa5on
automa5on
• Industrial
Automa5on
• Stock
Trading
Desks
– Borgs
trading
based
on
arbitrage
– Based
on
δt
• Cloud
Compu5ng/Storage
Clouds
• Telecommunica5ons
• Cellular/Network
frequency,
…
11. Industrial: RoboTeam in Action:
Process Relative Motion
(IEEE 1588 establishes timing
coordination)
12. T&M: data acquisition
• IEEE
1588
5me
stamping
data
at
the
sensor
for
aircraY
stress
tes5ng
Symmetricom GPS-linked
IEEE 1588 master clock
13. T&M: data acquisition
• Teletronics:
In-‐flight
Monitoring-‐
IEEE
1588
5me
stamping
data
at
source
14. T&M/Military: System
instrumentation
• Agilent
RF
and
high
speed
digital
instruments
(each
has
an
IEEE
1588
clock)
16. When I think of my own native land,
In a moment I seem to be there;
But, alas! recollection at hand
Soon hurries me back to despair.
- Cowper, The Solitude Of Alexander SelKirk
IEEE1588v2
PTP
(Precision
Time
Protocol)
17. Objec5ves
of
IEEE
1588
• Sub-‐microsecond
synchroniza5on
of
real-‐5me
clocks
in
components
of
a
networked
distributed
measurement
&
control
system
• Intended
for
rela5vely
localized
systems
typical
of
financial,
cloud
&
industrial
automa5on/test
&
measurement
environments.
• Applicable
to
local
area
networks
suppor5ng
mul5cast
communica5ons
(including
but
not
limited
to
Ethernet)
18. Objec5ves
of
IEEE
1588
• Simple,
administra5on
free
installa5on
• Support
heterogeneous
systems
of
clocks
with
varying
precision,
resolu5on
and
stability
• Minimal
resource
requirements
on
networks
and
host
components.
19. PTP Communication Ports on PTP
Devices
§ PTP uses Master-Slave model to provide packet based clock synchronization
over Unicast and/or Multicast transport
§ Timing distribution uses a series of messages between Master and Slave PTP
devices to achieve synchronization
§ PTP capable devices exchange messages through logical ports
§ There are three types of PTP port states:
– PTP Master Port/clock (M): has the best quality & distributes timing info to
Slaves.
– PTP Slave Port/clock (S): Synchronizes its clock with a Master port.
– PTP Passive Port: not a Master port, doesn’t synchronize to a Master port to
avoid loops
1588v2 1588v2 PRC
Clients (Slave) Master
BSC/RNC
IP/MPLS/MPLS-
TP
20. Device Roles: Clock Types for Nodes
§ There are five basic RNC/GPS
PTP devices of which
four are PTP clocks: GMC
– Ordinary Clock (OC) M M
– Boundary Clock (BC) S S
– End-to-End OC-0 BC-0
Transparent Clock M M
– Peer-to-Peer
transparent Clock S S
OC-1 OC-2
– Management node
§ Grand Master Clock
(GMC) PTP Domain
– Ultimate source of time RNC, GPS = External Primary Reference Clock
within a domain (OC or BC)
21. PTP Device Communication Messages
§ PTP devices communicate using a set of General messages and Event
Messages to achieve synchronization
§ General Messages play important role in synchronization and used to
discover PTP devices, build & maintain PTP session, are not time
stamped and consist of:
– Follow_up: also generate timing information
– Delay_Response: also generate timing information
– Pdelay_Resp_Follow_Up: used in measuring link delay
– Announce: establishes synchronization hierarchy/Device Discovery
– Management: query & update
– Signaling: for communication between clocks
§ Event Messages are time stamped by hardware and used for freq/time/
phase synchronization, and consist of:
– Sync
– Delay_Req
– Pdelay_Req and Pdelay_Resp
24. How Clock port role is determined
§ Best Master Clock Algorithm (BMCA)specifies how a
PTP port state transitions to different roles (Master,
Slave, Passive)
– Each clock determines the best master clock in its domain
out of all clocks it can see including itself – Grand Master
clock is defined
– Best clock is selected based upon multiple parameters
including user defined priority, clock class, accuracy and
stability of the local clock
– If there’s a tie, the decision is made upon Universally
Unique Identifier Device (UUID) of the port
– Port states (M/S/Pare defined
§ Port roles can be controlled dynamically for ex: default
IEEE 1588 BMCA or provisioned statically on a PTP
device using alternate BMCA
28. Lessons
• Shallow
Networks
• Separate
from
other
networks
• No
buffering
in
routers
• Accuracy
depends
on
Hardware/SoYware
• Normal
Distribu5on
rather
than
a
number
– Skinny
~50
μsecs
possible
• GPS
satellite
visibility
needed
for
Grand
Master
Clocks
• Most
of
financial
IT
isnin
basement
!
29. IETF
Tictoc
The woods are lovely, dark, and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep.
-Frost
30.
31. If a problem has no solution, it
is not a problem, but a fact,
not to be solved but to be
coped with, over time …
- Peres’s Law
ISPCS
2012