Lecture 2 — February 13, 2002 2.1 History
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Analysis of Server-Smartphone Application Communication Patterns
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Aaltodoc Publication Archive Aalto University School of Science Degree Programme in Computer Science and Engineering Péter Somogyi Analysis of server-smartphone application communication patterns Master’s Thesis Budapest, June 15, 2014 Supervisors: Professor Jukka Nurminen, Aalto University Professor Tamás Kozsik, Eötvös Loránd University Instructor: Máté Szalay-Bekő, M.Sc. Ph.D. Aalto University School of Science ABSTRACT OF THE Degree programme in Computer Science and MASTER’S THESIS Engineering Author: Péter Somogyi Title: Analysis of server-smartphone application communication patterns Number of pages: 83 Date: June 15, 2014 Language: English Professorship: Data Communication Code: T-110 Software Supervisor: Professor Jukka Nurminen, Aalto University Professor Tamás Kozsik, Eötvös Loránd University Instructor: Máté Szalay-Bekő, M.Sc. Ph.D. Abstract: The spread of smartphone devices, Internet of Things technologies and the popularity of web-services require real-time and always on applications. The aim of this thesis is to identify a suitable communication technology for server and smartphone communication which fulfills the main requirements for transferring real- time data to the handheld devices. For the analysis I selected 3 popular communication technologies that can be used on mobile devices as well as from commonly used browsers. These are client polling, long polling and HTML5 WebSocket. For the assessment I developed an Android application that receives real-time sensor data from a WildFly application server using the aforementioned technologies. Industry specific requirements were selected in order to verify the usability of this communication forms. The first one covers the message size which is relevant because most smartphone users have limited data plan. -
Performance of VBR Packet Video Communications on an Ethernet LAN: a Trace-Driven Simulation Study
9.3.1 Performance of VBR Packet Video Communications on an Ethernet LAN: A Trace-Driven Simulation Study Francis Edwards Mark Schulz edwardsF@sl .elec.uq.oz.au marksas1 .elec. uq.oz.au Department of Electrical and Computer Engineering The University of Queensland St. Lucia Q 4072 Australia Abstract medium term, we can expect that current LAN technolo- Provision of multimedia communication services on today’s gies will be utilized in the near term for packet transport of packet-switched network infrastructure is becoming increas- video applications [4,5, 61. Characterizing the performance ingly feasible. However, there remains a lack of information of current networks carrying video communications traffic is regarding the performance of multimedia sources operating therefore an important issue. This paper investigates packet in bursty data traffic conditions. In this study, a videotele- transport of real time video communications traffic, charac- phony system deployed on the Ethernet LAN is simulated, teristic of videotelephony applications, on the popular 10 employing high time-resolution LAN traces as the data traf- Mbit/s Ethernet LAN. fic load. In comparison with Poisson traffic models, the Previous work has established that Ethernet is capable of trace-driven cases produce highly variable packet delays, and supporting video communication traffic in the presence of higher packet loss, thereby degrading video traffic perfor- Poisson data traffic [6, 71. However, recent studies of high mance. In order to compensate for these effects, a delay time-resolution LAN traffic have observed highly bursty control scheme based on a timed packet dropping algorithm traffic patterns which sustain high variability over timescales is examined. -
Communication Protocol for Schools
Communication Protocol for Schools Communication plays a key role in creating and fostering strong, positive relationships between the school and the home. Communication is a two-way street; our schools share information with our families and community, and our families share information with our schools. The purpose of this document is to guide, manage and improve school-home communication by offering a standard format, structure and sequence for regular, ongoing communication. Communication Channels Communication can take place in a variety of formats. The message and the purpose of the communication can help determine which format is most appropriate. Generally, the more issues-driven and/or detailed the information is, the more direct the communication channel chosen should be. Communication channels include: Face-to-face communication – one-on-one meetings, School Council meetings, Parent-Student- Teacher interviews Telephone conversations Hard copy, written communication – letters sent home from the school, paper school newsletters Electronic communication – email, electronic newsletters, websites, social media When the communication requires a dialogue, such as bringing forward a question or concern or when a discussion is required on a particular topic, the preferred channels of communication are ones that allow for an immediate and ongoing interaction between the people involved. The best formats for this kind of communication are face-to-face conversations or telephone conversations. Schools and families are encouraged to use these direct channels of communication when a topic is complex or requires a dialogue. These more direct forms of communication also help us establish a personal connection, which helps build relationships that we don’t get in other forms of communication. -
Voice Over Internet Protocol (Voip): a Brief Review
© APR 2018 | IRE Journals | Volume 1 Issue 10 | ISSN: 2456-8880 Voice over Internet Protocol (VoIP): A Brief Review ANURAG K MADHESHIYA1, KIRAN S KALE2, SHIV K YADAV3, JIGNESHKUMAR R. VALVI4 1,2,3,4 Department of Electronics and Communication, SVNIT Surat, India Abstract -- VoIP stands for Voice over Inter Protocol. It is setting up calls, registering the calls, authenticating a communication protocol mainly used for voice and terminating the call. Protocol belonging to H.323 communication, data transfer and video calling. It is based family of protocol uses TCP and UDP connection for on packet transmission over internet network. Paul Baran transportation. For call registering and call signaling and other researchers developed the packet network in the H.225 protocol is used. For media session mid twentieth century. In 1973 Dany Cohen first demonstrated packet voice in flight simulator application. establishment and controlling H.245 is used. For Due to its digital nature it is easy to operate on this protocol. conferencing T.120 protocol is used [3]-[4]. Index Terms: MGCP, Packet, QoS, SIP I. INTRODUCTION Voice over Internet Protocol also known as Voice over IP and VoIP is a communication standard for transmission of voice signal, data transmission and video conferencing. Actually this technology follow packet switching. In packet switching first the input signal (voice, data, video) converted into digital form so other operation becomes simple after this we do encoding, compressing of digital data to make more secure transmission through channel. Then after this we transmit the signal over the channel. At receiver side we do reverse of it but it also require an addition block before receiver to store packets and reorder these packets because in packet switching different Figure 1: Call flow of H.323 packets follow different path so reaches in random manner. -
An Evaluation Protocol for Picture Archiving and Communication System: a Systematic Review
ORIGINAL PAPER An Evaluation Protocol for Picture Archiving and Communication System: a Systematic Review Mohsen S. Tabatabaei1, ABSTRACT Mostafa Langarizadeh1, Introduction: Picture archiving and communication system (PACS) serves to store, transmit, communi- Kamran Tavakol2 cate and manage medical images. A logical evaluation protocol assists to determine whether the system is technically, structurally and operationally fit. The purpose of this systematic review was to propose a 1Department of Health Information logical evaluation protocol for PACS, particularly useful for new hospitals and other healthcare institutions Management, School of Health Management and Information Sciences, Iran University of in developing countries. Methods and Materials: We systematically reviewed 25 out of 267 full-length Medical Sciences. Tehran, Iran articles, published between 2000 and 2017, retrieved from four sources: Science Direct, Scopus, PubMed 2School of Medicine, University of Maryland and Google Scholar. The extracted data were tabulated and reviewed successively by three independent Baltimore. Baltimore, MD, USA panels of experts that oversaw the design of this study and the process by which the PACS evaluation protocol was systematically developed. Results: The outcome data were ranked by expert panels and Corresponding author: Mohsen S. Tabatabaei, Tel: +98-990-188-0720. E-mail: [email protected] analyzed statistically, with the reliability established at 0.82 based on the Pearson’s correlation coefficient. The essential components and the best options to establish an optimal PACS were organized under nine main sections: system configuration; system network; data storage; data compression; image input; image doi: 10.5455/aim.2017.25.250-253 characteristics; image presentation; communication link; and system security, with a total of 20 compo- ACTA INFORM MED. -
Internet of Things (Iot): Protocols White Paper
INTERNET OF THINGS (IOT): PROTOCOLS WHITE PAPER 11 December 2020 Version 1 1 Hospitality Technology Next Generation Internet of Things (IoT) Security White Paper 11 December 2020 Version 1 About HTNG Hospitality Technology Next Generation (HTNG) is a non-profit association with a mission to foster, through collaboration and partnership, the development of next-generation systems and solutions that will enable hoteliers and their technology vendors to do business globally in the 21st century. HTNG is recognized as the leading voice of the global hotel community, articulating the technology requirements of hotel companies of all sizes to the vendor community. HTNG facilitate the development of technology models for hospitality that will foster innovation, improve the guest experience, increase the effectiveness and efficiency of hotels, and create a healthy ecosystem of technology suppliers. Copyright 2020, Hospitality Technology Next Generation All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of the copyright owner. For any software code contained within this specification, permission is hereby granted, free-of-charge, to any person obtaining a copy of this specification (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the above copyright notice and this permission notice being included in all copies or substantial portions of the Software. -
Packet Processing at Wire Speed Using Network Processors
Packet processing at wire speed using Network processors Chethan Kumar and Hao Che University of Texas at Arlington {ckumar, hche}@cse.uta.edu Abstract 1 Introduction Recent developments in fiber optics and the new The modern day Internet has seen an explosive bandwidth hungry applications have put more stress growth of applications being used on it. As more and on the active components (switches, routers etc.,) of a more applications are being developed, there is an network. Optical fiber bandwidth is no longer a increase in the amount of load put on the internet. At constraint for increasing the network bandwidth. the same time the fiber optics bandwidth has However, the processing power of the network has not increased dramatically to meet the traffic demand, but scaled upto the increase in the fiber bandwidth. the present day routers have limited processing power Communication industry is looking forward for more to handle this profound demand increase. Hence the innovative ways of designing router1 architecture and networking and telecommunications industry is research is being conducted to develop a scalable, compelled to look for new solutions for improving flexible and cost-effective architecture for routers. A the performance and the processing power of the successful outcome of this effort is a specialized routers. processor called Network processor. Network processor provides performance at hardware speeds One of the industry’s solutions to the challenges while attaining the flexibility of software. Network posed by the increased demand for the processing processors from different vendors employ different power is programmable functional units grouped into architectures and the choice of a particular type of a processor called Application Specific Instruction network processor can affect the architecture of the Processor (ASIP) or Network processor (NP)2. -
Packet Processing Execution Engine (PROX) - Performance Characterization for NFVI User Guide
USER GUIDE Intel Corporation Packet pROcessing eXecution Engine (PROX) - Performance Characterization for NFVI User Guide Authors 1 Introduction Yury Kylulin Properly designed Network Functions Virtualization Infrastructure (NFVI) environments deliver high packet processing rates, which are also a required dependency for Luc Provoost onboarded network functions. NFVI testing methodology typically includes both Petar Torre functionality testing and performance characterization testing, to ensure that NFVI both exposes the correct APIs and is capable of packet processing. This document describes how to use open source software tools to automate peak traffic (also called saturation) throughput testing to characterize the performance of a containerized NFVI system. The text and examples in this document are intended for architects and testing engineers for Communications Service Providers (CSPs) and their vendors. This document describes tools used during development to evaluate whether or not a containerized NFVI can perform the required rates of packet processing within set packet drop rates and latency percentiles. This document is part of the Network Transformation Experience Kit, which is available at https://networkbuilders.intel.com/network-technologies/network-transformation-exp- kits. 1 User Guide | Packet pROcessing eXecution Engine (PROX) - Performance Characterization for NFVI Table of Contents 1 Introduction ................................................................................................................................................................................................................ -
Lora-Based Device-To-Device Smartphone Communication for Crisis Scenarios
Jonas Höchst et al. LoRa-based Device-to-Device Smartphone Communication for Crisis Scenarios LoRa-based Device-to-Device Smartphone Communication for Crisis Scenarios Jonas Höchst Lars Baumgärtner University of Marburg, Germany Technical University of Darmstadt, Germany Technical University of Darmstadt, Germany [email protected] [email protected] Franz Kuntke Alvar Penning Technical University of Darmstadt, Germany University of Marburg, Germany [email protected] [email protected] Artur Sterz Bernd Freisleben University of Marburg, Germany University of Marburg, Germany Technical University of Darmstadt, Germany Technical University of Darmstadt, Germany [email protected] [email protected] ABSTRACT In this paper, we present an approach to facilitate long-range device-to-device communication via smartphones in crisis scenarios. Through a custom firmware for low-cost LoRa capable micro-controller boards, called rf95modem, common devices for end users can be enabled to use LoRa through a Bluetooth, Wi-Fi, or serial connection. We present two applications utilizing the flexibility provided by the proposed firmware. First, we introduce a novel device-to-device LoRa chat application that works a) on the two major mobile platforms Android and iOS and b) on traditional computers like notebooks using a console-based interface. Second, we demonstrate how other infrastructure-less technology can benefit from our approach by integrating it into the DTN7 delay-tolerant networking software. The firmware, the device-to-device chat application, the integration into DTN7, as well as the experimental evaluation code fragments are available under permissive open-source licenses. Keywords LoRa, Disaster Communication, Device-To-Device Communication, INTRODUCTION The communication technologies developed and deployed in the last decades are integral parts of our daily life and are used by mobile phones, computers, or smart applications in homes and cities. -
Lightweight Internet Protocol Stack Ideal Choice for High-Performance HFT and Telecom Packet Processing Applications Lightweight Internet Protocol Stack
GE Intelligent Platforms Lightweight Internet Protocol Stack Ideal Choice for High-Performance HFT and Telecom Packet Processing Applications Lightweight Internet Protocol Stack Introduction The number of devices connected to IP networks will be nearly three times as high as the global population in 2016. There will be nearly three networked devices per capita in 2016, up from over one networked device per capita in 2011. Driven in part by the increase in devices and the capabilities of those devices, IP traffic per capita will reach 15 gigabytes per capita in 2016, up from 4 gigabytes per capita in 2011 (Cisco VNI). Figure 1 shows the anticipated growth in IP traffic and networked devices. The IP traffic is increasing globally at the breath-taking pace. The rate at which these IP data packets needs to be processed to ensure not only their routing, security and delivery in the core of the network but also the identification and extraction of payload content for various end-user applications such as high frequency trading (HFT), has also increased. In order to support the demand of high-performance IP packet processing, users and developers are increasingly moving to a novel approach of combining PCI Express packet processing accelerator cards in a standalone network server to create an accelerated network server. The benefits of using such a hardware solu- tion are explained in the GE Intelligent Platforms white paper, Packet Processing in Telecommunications – A Case for the Accelerated Network Server. 80 2016 The number of networked devices -
High Level Synthesis for Packet Processing Pipelines Cristian
High Level Synthesis for Packet Processing Pipelines Cristian Soviani Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2007 c 2007 Cristian Soviani All Rights Reserved ABSTRACT High Level Synthesis for Packet Processing Pipelines Cristian Soviani Packet processing is an essential function of state-of-the-art network routers and switches. Implementing packet processors in pipelined architectures is a well-known, established technique, albeit different approaches have been proposed. The design of packet processing pipelines is a delicate trade-off between the desire for abstract specifications, short development time, and design maintainability on one hand and very aggressive performance requirements on the other. This thesis proposes a coherent design flow for packet processing pipelines. Like the design process itself, I start by introducing a novel domain-specific language that provides a high-level specification of the pipeline. Next, I address synthesizing this model and calculating its worst-case throughput. Finally, I address some specific circuit optimization issues. I claim, based on experimental results, that my proposed technique can dramat- ically improve the design process of these pipelines, while the resulting performance matches the expectations of hand-crafted design. The considered pipelines exhibit a pseudo-linear topology, which can be too re- strictive in the general case. However, especially due to its high performance, such an architecture may be suitable for applications outside packet processing, in which case some of my proposed techniques could be easily adapted. Since I ran my experiments on FPGAs, this work has an inherent bias towards that technology; however, most results are technology-independent. -
Evaluating the Power of Flexible Packet Processing for Network Resource Allocation Naveen Kr
Evaluating the Power of Flexible Packet Processing for Network Resource Allocation Naveen Kr. Sharma, Antoine Kaufmann, and Thomas Anderson, University of Washington; Changhoon Kim, Barefoot Networks; Arvind Krishnamurthy, University of Washington; Jacob Nelson, Microsoft Research; Simon Peter, The University of Texas at Austin https://www.usenix.org/conference/nsdi17/technical-sessions/presentation/sharma This paper is included in the Proceedings of the 14th USENIX Symposium on Networked Systems Design and Implementation (NSDI ’17). March 27–29, 2017 • Boston, MA, USA ISBN 978-1-931971-37-9 Open access to the Proceedings of the 14th USENIX Symposium on Networked Systems Design and Implementation is sponsored by USENIX. Evaluating the Power of Flexible Packet Processing for Network Resource Allocation Naveen Kr. Sharma∗ Antoine Kaufmann∗ Thomas Anderson∗ Changhoon Kim† Arvind Krishnamurthy∗ Jacob Nelson‡ Simon Peter§ Abstract of the packet header, perform simple computations on Recent hardware switch architectures make it feasible values in packet headers, and maintain mutable state that to perform flexible packet processing inside the net- preserves the results of computations across packets. Im- work. This allows operators to configure switches to portantly, these advanced data-plane processing features parse and process custom packet headers using flexi- operate at line rate on every packet, addressing a ma- ble match+action tables in order to exercise control over jor limitation of earlier solutions such as OpenFlow [22] how packets are processed and routed. However, flexible which could only operate on a small fraction of packets, switches have limited state, support limited types of op- e.g., for flow setup. FlexSwitches thus hold the promise erations, and limit per-packet computation in order to be of ushering in the new paradigm of a software defined able to operate at line rate.