6.02 Fall 2012 Lecture #23 the Dawn of Packet Switching ARPANET Initial Baby Steps
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Lecture 10: Switching & Internetworking
Lecture 10: Switching & Internetworking CSE 123: Computer Networks Alex C. Snoeren HW 2 due WEDNESDAY Lecture 10 Overview ● Bridging & switching ◆ Spanning Tree ● Internet Protocol ◆ Service model ◆ Packet format CSE 123 – Lecture 10: Internetworking 2 Selective Forwarding ● Only rebroadcast a frame to the LAN where its destination resides ◆ If A sends packet to X, then bridge must forward frame ◆ If A sends packet to B, then bridge shouldn’t LAN 1 LAN 2 A W B X bridge C Y D Z CSE 123 – Lecture 9: Bridging & Switching 3 Forwarding Tables ● Need to know “destination” of frame ◆ Destination address in frame header (48bit in Ethernet) ● Need know which destinations are on which LANs ◆ One approach: statically configured by hand » Table, mapping address to output port (i.e. LAN) ◆ But we’d prefer something automatic and dynamic… ● Simple algorithm: Receive frame f on port q Lookup f.dest for output port /* know where to send it? */ If f.dest found then if output port is q then drop /* already delivered */ else forward f on output port; else flood f; /* forward on all ports but the one where frame arrived*/ CSE 123 – Lecture 9: Bridging & Switching 4 Learning Bridges ● Eliminate manual configuration by learning which addresses are on which LANs Host Port A 1 ● Basic approach B 1 ◆ If a frame arrives on a port, then associate its source C 1 address with that port D 1 ◆ As each host transmits, the table becomes accurate W 2 X 2 ● What if a node moves? Table aging Y 3 ◆ Associate a timestamp with each table entry Z 2 ◆ Refresh timestamp for each -
Wifi Direct Internetworking
WiFi Direct Internetworking António Teólo∗† Hervé Paulino João M. Lourenço ADEETC, Instituto Superior de NOVA LINCS, DI, NOVA LINCS, DI, Engenharia de Lisboa, Faculdade de Ciências e Tecnologia, Faculdade de Ciências e Tecnologia, Instituto Politécnico de Lisboa Universidade NOVA de Lisboa Universidade NOVA de Lisboa Portugal Portugal Portugal [email protected] [email protected] [email protected] ABSTRACT will enable WiFi communication range and speed even in cases of: We propose to interconnect mobile devices using WiFi-Direct. Hav- network infrastructure congestion, which may happen in highly ing that, it will be possible to interconnect multiple o-the-shelf crowded venues (such as sports and cultural events); or temporary, mobile devices, via WiFi, but without any supportive infrastructure. or permanent, absence of infrastructure, as may happen in remote This will pave the way for mobile autonomous collaborative sys- locations or disaster situations. tems that can operate in any conditions, like in disaster situations, WFD allows devices to form groups, with one of them, called in very crowded scenarios or in isolated areas. This work is relevant Group Owner (GO), acting as a soft access point for remaining since the WiFi-Direct specication, that works on groups of devices, group members. WFD oers node discovery, authentication, group does not tackle inter-group communication and existing research formation and message routing between nodes in the same group. solutions have strong limitations. However, WFD communication is very constrained, current imple- We have a two phase work plan. Our rst goal is to achieve mentations restrict group size 9 devices and none of these devices inter-group communication, i.e., enable the ecient interconnec- may be a member of more than one WFD group. -
Guidelines on Mobile Device Forensics
NIST Special Publication 800-101 Revision 1 Guidelines on Mobile Device Forensics Rick Ayers Sam Brothers Wayne Jansen http://dx.doi.org/10.6028/NIST.SP.800-101r1 NIST Special Publication 800-101 Revision 1 Guidelines on Mobile Device Forensics Rick Ayers Software and Systems Division Information Technology Laboratory Sam Brothers U.S. Customs and Border Protection Department of Homeland Security Springfield, VA Wayne Jansen Booz-Allen-Hamilton McLean, VA http://dx.doi.org/10.6028/NIST.SP. 800-101r1 May 2014 U.S. Department of Commerce Penny Pritzker, Secretary National Institute of Standards and Technology Patrick D. Gallagher, Under Secretary of Commerce for Standards and Technology and Director Authority This publication has been developed by NIST in accordance with its statutory responsibilities under the Federal Information Security Management Act of 2002 (FISMA), 44 U.S.C. § 3541 et seq., Public Law (P.L.) 107-347. NIST is responsible for developing information security standards and guidelines, including minimum requirements for Federal information systems, but such standards and guidelines shall not apply to national security systems without the express approval of appropriate Federal officials exercising policy authority over such systems. This guideline is consistent with the requirements of the Office of Management and Budget (OMB) Circular A-130, Section 8b(3), Securing Agency Information Systems, as analyzed in Circular A- 130, Appendix IV: Analysis of Key Sections. Supplemental information is provided in Circular A- 130, Appendix III, Security of Federal Automated Information Resources. Nothing in this publication should be taken to contradict the standards and guidelines made mandatory and binding on Federal agencies by the Secretary of Commerce under statutory authority. -
Growth of the Internet
Growth of the Internet K. G. Coffman and A. M. Odlyzko AT&T Labs - Research [email protected], [email protected] Preliminary version, July 6, 2001 Abstract The Internet is the main cause of the recent explosion of activity in optical fiber telecommunica- tions. The high growth rates observed on the Internet, and the popular perception that growth rates were even higher, led to an upsurge in research, development, and investment in telecommunications. The telecom crash of 2000 occurred when investors realized that transmission capacity in place and under construction greatly exceeded actual traffic demand. This chapter discusses the growth of the Internet and compares it with that of other communication services. Internet traffic is growing, approximately doubling each year. There are reasonable arguments that it will continue to grow at this rate for the rest of this decade. If this happens, then in a few years, we may have a rough balance between supply and demand. Growth of the Internet K. G. Coffman and A. M. Odlyzko AT&T Labs - Research [email protected], [email protected] 1. Introduction Optical fiber communications was initially developed for the voice phone system. The feverish level of activity that we have experienced since the late 1990s, though, was caused primarily by the rapidly rising demand for Internet connectivity. The Internet has been growing at unprecedented rates. Moreover, because it is versatile and penetrates deeply into the economy, it is affecting all of society, and therefore has attracted inordinate amounts of public attention. The aim of this chapter is to summarize the current state of knowledge about the growth rates of the Internet, with special attention paid to the implications for fiber optic transmission. -
Research on the System Structure of IPV9 Based on TCP/IP/M
International Journal of Advanced Network, Monitoring and Controls Volume 04, No.03, 2019 Research on the System Structure of IPV9 Based on TCP/IP/M Wang Jianguo Xie Jianping 1. State and Provincial Joint Engineering Lab. of 1. Chinese Decimal Network Working Group Advanced Network, Monitoring and Control Shanghai, China 2. Xi'an, China Shanghai Decimal System Network Information 2. School of Computer Science and Engineering Technology Ltd. Xi'an Technological University e-mail: [email protected] Xi'an, China e-mail: [email protected] Wang Zhongsheng Zhong Wei 1. School of Computer Science and Engineering 1. Chinese Decimal Network Working Group Xi'an Technological University Shanghai, China Xi'an, China 2. Shanghai Decimal System Network Information 2. State and Provincial Joint Engineering Lab. of Technology Ltd. Advanced Network, Monitoring and Control e-mail: [email protected] Xi'an, China e-mail: [email protected] Abstract—Network system structure is the basis of network theory, which requires the establishment of a link before data communication. The design of network model can change the transmission and the withdrawal of the link after the network structure from the root, solve the deficiency of the transmission is completed. It solves the problem of original network system, and meet the new demand of the high-quality real-time media communication caused by the future network. TCP/IP as the core network technology is integration of three networks (communication network, successful, it has shortcomings but is a reasonable existence, broadcasting network and Internet) from the underlying will continue to play a role. Considering the compatibility with structure of the network, realizes the long-distance and the original network, the new network model needs to be large-traffic data transmission of the future network, and lays compatible with the existing TCP/IP four-layer model, at the a solid foundation for the digital currency and virtual same time; it can provide a better technical system to currency of the Internet. -
Multimedia, Internet, On-Line
Section IV: Multimedia, the Internet, and On-Line Services High-End Digital Video Applications Larry Amiot Electronic and Computing Technologies Division Argonne National Laboratory The emphasis of this paper is on the high-end applications Internet and Intranet that are driving digital video. The research with which I am involved at Argonne National Laboratory is not done on dig- The packet video networks which currently support many ital video per se, but rather on how the research applications applications such as file transfer, Mbone video (talking at the laboratory drive its requirements for digital video. The heads), and World Wide Web browsing are limiting for high- paper will define what digital video is, what some of its com- quality video because of the low throughput one can achieve ponents are, and then discuss a few applications that are dri- via the Internet or intranets. Examples of national packet ving the development of these components. The focus will be switched networks developed in the last several years include on what digital video means to individuals in the research the National Science Foundation Network (NSFNet). The and education community. Department of Energy had its own network called ESNET, and the National Aeronautics and Space Administration The Digital Video Environment (NASA) had a network as well. Recently, the NSFNet was de- commissioned, and commercial interests are now starting to In 1996, a group of people from several universities in the fill that void. Research and education communities are find- Midwest and from Argonne formed a Video Working Group. ing, however, that this new commercial Internet is too re- This body tried to define the areas of digital video of impor- stricting and does not meet their throughput requirements; it tance to their institutions. -
F. Circuit Switching
CSE 3461: Introduction to Computer Networking and Internet Technologies Circuit Switching Presentation F Study: 10.1, 10.2, 8 .1, 8.2 (without SONET/SDH), 8.4 10-02-2012 A Closer Look At Network Structure: • network edge: applications and hosts • network core: —routers —network of networks • access networks, physical media: communication links d. xuan 2 1 The Network Core • mesh of interconnected routers • the fundamental question: how is data transferred through net? —circuit switching: dedicated circuit per call: telephone net —packet-switching: data sent thru net in discrete “chunks” d. xuan 3 Network Layer Functions • transport packet from sending to receiving hosts application transport • network layer protocols in network data link network physical every host, router network data link network data link physical data link three important functions: physical physical network data link • path determination: route physical network data link taken by packets from source physical to dest. Routing algorithms network network data link • switching: move packets from data link physical physical router’s input to appropriate network data link application router output physical transport network data link • call setup: some network physical architectures require router call setup along path before data flows d. xuan 4 2 Network Core: Circuit Switching End-end resources reserved for “call” • link bandwidth, switch capacity • dedicated resources: no sharing • circuit-like (guaranteed) performance • call setup required d. xuan 5 Circuit Switching • Dedicated communication path between two stations • Three phases — Establish (set up connection) — Data Transfer — Disconnect • Must have switching capacity and channel capacity to establish connection • Must have intelligence to work out routing • Inefficient — Channel capacity dedicated for duration of connection — If no data, capacity wasted • Set up (connection) takes time • Once connected, transfer is transparent • Developed for voice traffic (phone) g. -
Design of a Lan-Based Voice Over Ip (Voip) Telephone System
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by KhartoumSpace DESIGN OF A LAN-BASED VOICE OVER IP (VOIP) TELEPHONE SYSTEM A thesis submitted to the University of Khartoum in partial fulfillment of the requirement for the degree of MSC in Communication & Information Systems BY HASSAN SULEIMAN ABDALLA OMER B.SC of Electrical Engineering (2000) University of Khartoum Supervisor Dr. MOHAMMED ALI HAMAD ABBAS Faculty of Engineering & Architecture Department of Electrical & Electronics Engineering SEPTEMBER 2009 ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ ﺻﺪق اﷲ اﻟﻌﻈﻴﻢ iii ACKNOWLEDGEMENTS First I would like to thanks my supervisor Dr. Mohammed Ali Hamad Abbas, because this research project would not have been possible without his support and guidance; so I take this opportunity to offer him my gratitude for his patience ,support and guidance . Special thanks to the Department of Electrical and Electronics Engineering University Of Khartoum for their facilities, also I would like to convey my thanks to the staff member of MSc program for their help and to all my colleges in the MSc program. It is with great affection and appreciation that I acknowledge my indebtedness to my parents for their understanding & endless love. H.Suleiman iv Abstract The objective of this study was to design a program to transmit voice conversations over data network using the internet protocol –Voice Over IP (VOIP). JAVA programming language was used to design the client-server model, codec and socket interfaces. The design was fully explained as to its input, processing and output. The test of the designed voice over IP model was successful, although some delay in receiving the conversation was noticed. -
I: the Conception
Excerpt from: Mayo, Keenan and Newcomb, Peter. “How the Web Was Won,” Vanity Fair, July 2008. I: The Conception Paul Baran, an electrical engineer, conceived one of the Internet’s building blocks—packet switching— while working at the Rand Corporation around 1960. Packet switching breaks data into chunks, or “packets,” and lets each one take its own path to a destination, where they are re-assembled (rather than sending everything along the same path, as a traditional telephone circuit does). A similar idea was proposed independently in Britain by Donald Davies. Later in his career, Baran would pioneer the airport metal detector. Paul Baran: It was necessary to have a strategic system that could withstand a first attack and then be able to return the favor in kind. The problem was that we didn’t have a survivable communications system, and so Soviet missiles aimed at U.S. missiles would take out the entire telephone- communication system. At that time the Strategic Air Command had just two forms of communication. One was the U.S. telephone system, or an overlay of that, and the other was high-frequency or shortwave radio. So that left us with the interesting situation of saying, Well, why do the communications fail when the bombs were aimed, not at the cities, but just at the strategic forces? And the answer was that the collateral damage was sufficient to knock out a telephone system that was highly centralized. Well, then, let’s not make it centralized. Let’s spread it out so that we can have other paths to get around the damage. -
The Internet ! Based on Slides Originally Published by Thomas J
15-292 History of Computing The Internet ! Based on slides originally published by Thomas J. Cortina in 2004 for a course at Stony Brook University. Revised in 2013 by Thomas J. Cortina for a computing history course at Carnegie Mellon University. A Vision of Connecting the World – the Memex l Proposed by Vannevar Bush l first published in the essay "As We May Think" in Atlantic Monthly in 1945 and subsequently in Life Magazine. l "a device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility" l also indicated the idea that would become hypertext l Bush’s work was influential on all Internet pioneers The Memex The Impetus to Act l 1957 - U.S.S.R. launches Sputnik I into space l 1958 - U.S. Department of Defense responds by creating ARPA l Advanced Research Projects Agency l “mission is to maintain the technological superiority of the U.S. military” l “sponsoring revolutionary, high-payoff research that bridges the gap between fundamental discoveries and their military use.” l Name changed to DARPA (Defense) in 1972 ARPANET l The Advanced Research Projects Agency Network (ARPANET) was the world's first operational packet switching network. l Project launched in 1968. l Required development of IMPs (Interface Message Processors) by Bolt, Beranek and Newman (BBN) l IMPs would connect to each other over leased digital lines l IMPs would act as the interface to each individual host machine l Used packet switching concepts published by Leonard Kleinrock, most famous for his subsequent books on queuing theory Early work Baran (L) and Davies (R) l Paul Baran began working at the RAND corporation on secure communications technologies in 1959 l goal to enable a military communications network to withstand a nuclear attack. -
Features of the Internet History the Norwegian Contribution to the Development PAAL SPILLING and YNGVAR LUNDH
Features of the Internet history The Norwegian contribution to the development PAAL SPILLING AND YNGVAR LUNDH This article provides a short historical and personal view on the development of packet-switching, computer communications and Internet technology, from its inception around 1969 until the full- fledged Internet became operational in 1983. In the early 1990s, the internet backbone at that time, the National Science Foundation network – NSFNET, was opened up for commercial purposes. At that time there were already several operators providing commercial services outside the internet. This presentation is based on the authors’ participation during parts of the development and on literature Paal Spilling is studies. This provides a setting in which the Norwegian participation and contribution may be better professor at the understood. Department of informatics, Univ. of Oslo and University 1 Introduction Defense (DOD). It is uncertain when DoD really Graduate Center The concept of computer networking started in the standardized on the entire protocol suite built around at Kjeller early 1960s at the Massachusetts Institute of Technol- TCP/IP, since for several years they also followed the ogy (MIT) with the vision of an “On-line community ISO standards track. of people”. Computers should facilitate communica- tions between people and be a support for human The development of the Internet, as we know it today, decision processes. In 1961 an MIT PhD thesis by went through three phases. The first one was the Leonard Kleinrock introduced some of the earliest research and development phase, sponsored and theoretical results on queuing networks. Around the supervised by ARPA. Research groups that actively same time a series of Rand Corporation papers, contributed to the development process and many mainly authored by Paul Baran, sketched a hypotheti- who explored its potential for resource sharing were cal system for communication while under attack that permitted to connect to and use the network. -
Internetworking and Layered Models
1 Internetworking and Layered Models The Internet today is a widespread information infrastructure, but it is inherently an insecure channel for sending messages. When a message (or packet) is sent from one Website to another, the data contained in the message are routed through a number of intermediate sites before reaching its destination. The Internet was designed to accom- modate heterogeneous platforms so that people who are using different computers and operating systems can communicate. The history of the Internet is complex and involves many aspects – technological, organisational and community. The Internet concept has been a big step along the path towards electronic commerce, information acquisition and community operations. Early ARPANET researchers accomplished the initial demonstrations of packet- switching technology. In the late 1970s, the growth of the Internet was recognised and subsequently a growth in the size of the interested research community was accompanied by an increased need for a coordination mechanism. The Defense Advanced Research Projects Agency (DARPA) then formed an International Cooperation Board (ICB) to coordinate activities with some European countries centered on packet satellite research, while the Internet Configuration Control Board (ICCB) assisted DARPA in managing Internet activity. In 1983, DARPA recognised that the continuing growth of the Internet community demanded a restructuring of coordination mechanisms. The ICCB was dis- banded and in its place the Internet Activities Board (IAB) was formed from the chairs of the Task Forces. The IAB revitalised the Internet Engineering Task Force (IETF) as a member of the IAB. By 1985, there was a tremendous growth in the more practical engineering side of the Internet.