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Computer network

Computer network
Computer networks differ in the physical media used to transmit their signals, the communications protocols to organize network traffic, the network's size, topology and organizational intent. In most cases, communications protocols are layered on (i.e. work using) other more specific or more general communications protocols, except for the physical layer that directly deals with the physical media. Computer networks support applications such as access to the World Wide Web, shared use of application and storage servers, printers, and fax machines, and use of email and instant messaging applications. History[edit] A computer network, or simply a network, is a collection of computers and other hardware components interconnected by communication channels that allow sharing of resources and information. The following is a chronology of significant computer network developments: Properties[edit] Network packet[edit] Main article: Network packet Network topology[edit] Network links[edit] Related:  Social Media Training From Rookie to Expert

Critical Mass and Your Social Media Strategy Part I Tipping the Scale If ever I needed a reminder about what really matters to advertisers, I got it earlier this month at the tech-media-gadget-advertising-palooza otherwise known as CES in Las Vegas. Simply put, in the 30+ meetings Microsoft Advertising held with... Microsoft, Warner Bros. Today is a definite first for me, and for Microsoft Advertising, as we launch the new campaign for The Hobbit: Desolation of Smaug on Windows 8 Ads-in-Apps, followed by a cross-platform solution on MSN and Xbox 360 on 13 December. Microsoft and AOL Partner to Bring Video to MSN and Bing Apps Today, in partnership with our friends at AOL, I’m happy to announce a content distribution agreement that will bring some of the best video content available from AOL to Microsoft’s video platforms, including MSN, with an audience of nearly 450... Teachers for Tomorrow: Recruiting Generation Next Our Fight Against Fraud Advertising fraud is a complex and constantly changing problem for our industry.

Communications protocol In telecommunications, a communications protocol is a system of digital rules for data exchange within or between computers. In computer science, when data is exchanged through a computer network, the rules system is called a network protocol. Communicating systems use well-defined formats for exchanging messages. Each message has an exact meaning intended to provoke a particular response of the receiver. Communicating systems[edit] In digital computing systems, the rules can be expressed by algorithms and data structures. Operating systems usually consist of a set of cooperating processes that manipulate shared data to communicate with each other. In contrast, because there is no common memory, communicating systems have to communicate with each other using a shared transmission medium. To implement a networking protocol, the protocol software modules are interfaced with a framework implemented on the machine's operating system. Basic requirements of protocols[edit] Protocol design[edit]

Internet U.S. Army soldiers "surfing the Internet" at Forward Operating Base Yusifiyah, Iraq The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (TCP/IP) to link several billion devices worldwide. The origins of the Internet date back to research commissioned by the United States government in the 1960s to build robust, fault-tolerant communication via computer networks.[2] This work, combined with efforts in the United Kingdom and France, led to the primary precursor network, the ARPANET, in the United States. Most traditional communications media, including telephony and television, are being reshaped or redefined by the Internet, giving birth to new services such as voice over Internet Protocol (VoIP) and Internet Protocol television (IPTV). Terminology The Internet, referring to the specific global system of interconnected IP networks, is a proper noun and written with an initial capital letter. History T3 NSFNET Backbone, c. 1992.

Report: Facebook working to improve its 'search' technology High performance access to file storage Facebook is reportedly working on an overhaul to its clumsy search option. According to Bloomberg Businessweek, which cites two people familiar with the project, the company is attempting to improve the feature. Lars Rasmussen - who built the original Google Maps alongside his brother Jens before taking charge of the unloved and quickly dumped Google Wave - defected from the Chocolate Factory to Facebook in October 2010. He is now said to be beavering away at improving search for the Mark Zuckerberg-run company, which is currently in a quiet period ahead of its IPO that could happen as soon as next month. Apparently, Rasmussen is working on the project with around 25 engineers and they are focusing on making Facebook return more intelligent search queries. That's hardly surprising given that the "Like" feature is what Facebookers click on when they 'fess up to being a fan of, say, Justin Bieber, baked beans or incontinence pads.

OSI model Model with 7 layers to describe communications systems The Open Systems Interconnection model (OSI model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology. Its goal is the interoperability of diverse communication systems with standard protocols. The model partitions a communication system into abstraction layers. The original version of the model defined seven layers. A layer serves the layer above it and is served by the layer below it. The model is a product of the Open Systems Interconnection project at the International Organization for Standardization (ISO). Communication in the OSI-Model (example with layers 3 to 5) History[edit] In the late 1970s, the International Organization for Standardization (ISO) conducted a program to develop general standards and methods of networking. Description of OSI layers[edit] Layer 1: Physical Layer[edit]

A Brief History of Blogging Blogs have become an integral part of online culture. Practically everyone reads blogs now, whether they’re “official” news blogs associated with traditional news media, topic-based blogs related to one’s work or hobbies, or blogs purely for entertainment, just about anyone you ask has at least one favorite blog. But it wasn’t always so. Blogs have a relatively short history, even when compared with the history of the Internet itself. And it’s only in the past five to ten years that they’ve really taken off and become an important part of the online landscape. The Early Years It’s generally recognized that the first blog was Links.net, created by Justin Hall, while he was a Swarthmore College student in 1994. It wasn’t until 1997 that the term “weblog” was coined. 1998 marks the first known instance of a blog on a traditional news site, when Jonathan Dube blogged Hurricane Bonnie for The Charlotte Observer. “Weblog” was shortened to “blog” in 1999 by programmer Peter Merholz.

The TCP/IP Guide I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. If you like The TCP/IP Guide, please consider the download version. If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. Thanks for your understanding! Sincerely, Charles Kozierok Author and Publisher, The TCP/IP Guide Telecommunications network Example of how nodes may be interconnected with links to form a telecommunications network. This example is tree-like but many networks have loops. Each terminal in the network usually has a unique address so messages or connections can be routed to the correct recipients. The collection of addresses in the network is called the address space. Examples of telecommunications networks are: Messages and protocols[edit] Messages are generated by a sending terminal, then pass through the network of links and nodes until they arrive at the destination terminal. Components[edit] All telecommunication networks are made up of five basic components that are present in each network environment regardless of type or use. Early networks were built without computers, but late in the 20th century their switching centers were computerized or the networks replaced with computer networks. Network structure[edit] Example: the TCP/IP data network[edit] The area of the network size is between LANs and WANs.

How To Fix Computer Issues Registry errors are often a leading cause of Computer issues. The registry stores information about your computer's system hardware, software, and configuration settings. When registry information gets damaged, it can result in errors, crashes, program lock-ups and hardware failure. It is highly recommended that you fix this before it causes serious issues with your computer! Follow these 3 steps to fix Computer problems: 1. PC Cleaner Pro works with Windows 7, Windows Vista and Windows XP. Download Computer Error Repair Tool *File size: 3.9MB, Download time: <1min (Cable/DSL)Disclaimer: FixErrors.com is an authorized distributor of PC Cleaner.

Industrial Ethernet Industrial Ethernet (IE) refers to the use of standard Ethernet protocols with rugged connectors and extended temperature switches in an industrial environment, for automation or process control. Components used in plant process areas must be designed to work in harsh environments of temperature extremes, humidity, and vibration that exceed the ranges for information technology equipment intended for installation in controlled environments. The use of fiber Ethernet reduces the problems of electrical noise and provides electrical isolation to prevent equipment damage. Some industrial networks emphasized deterministic delivery of transmitted data, whereas Ethernet used collision detection which made transport time for individual data packets difficult to estimate with increasing network traffic. Application environment[edit] Industrial networks often use network switches to segment a large system into logical sub-networks, divided by address, protocol, or application. See also[edit]

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