One minute your wireless Internet is working fine. The next minute, it takes an infuriatingly slow five seconds to load a single Web page. You paid for the fastest Internet speed available but during these all-too-frequent times, it seems like the connection barely works at all.
“Most people think it’s a mystery,” said Aleksandar Kuzmanovic, associate professor of electrical engineering and computer science at Northwestern University’s McCormick School of Engineering. “They get upset at their routers. But what’s really happening is that your neighbor is watching Netflix.”
Most people don’t realize how much their neighbors’ Internet networks interfere with their own, heavily affecting speed and performance. Unless a home is located in the middle of nowhere, it is likely that neighboring homes’ Wi-Fi networks will bump into each other and prevent data from getting through. This is particularly true in large, urban apartment buildings where many people reside within a smaller area.
Kuzmanovic and his PhD students Marcel Flores and Uri Klarman have found that problems caused by competing networks can be mitigated by using an already-existing, extremely cheap medium: FM radio. Flores will present this work Tuesday,
If you have multiple computers in your home, networking them is a great idea! There are several big advantages to setting up an in-home network:
- If one of the computers has a printer attached, then the other computer can print to it over the network.
- If one of the computers has certain files on it, someone on the other computer can access those files over the network rather than having to copy them onto a disk or memory stick.
- If you like playing multi-user computer games that have network capabilities built in, then two people can play these games together over the network.
- If you connect to the Internet with one of the computers, the other computer can use that same connection over the network. So one computer can connect to the Internet with a modem and the other computer will route its Internet traffic through that single connection.
Networking PCs has gotten easier and a lot less expensive, but it is still a little bit of a challenge. How Home Networking Works discusses the whole thing in detail, but see the next page to see some quick answers.
Powerful computers made up of physically separate modules, self-organising networks, and computing inspired by biological systems are three hot research topics coming together in one European project.
European researchers have developed an innovative computing platform. At the heart of the system are many small modules, each made from chips with an inbuilt ability to learn. A self-configuring wireless network connects the modules, allowing them to operate as a coherent group.
Evolving to suit the task in hand and acting on information about their environment, such systems are described by their developers as “bio-inspired.” They are well suited to building mathematical models of scientific problems in which complexity arises from simple building blocks, such as in brains, stock markets, and the spread of new ideas.
Researchers already use programs that can learn — neural networks — to study problems like these. Their simulations would run faster if they could hard-wire instructions into computer chips rather than load them as software, but normally this would stop the machines from learning. Chips that learn by physically reconfiguring themselves therefore offer the best of both worlds.
Large numbers of computers
If you were a programmer, you would really love Cloud Computing System. As Cloud Computing system continues to develop new features, there will be just more and more things to be a lot of step forward. It makes you feel free of using the programming language by your own choice. Luckily, Atlantic.Net, a privately held hosting solutions provider has released a free application programming interface (API) for its cloud computing platform. It makes Cloud Computing system a lot of easier to be used by user in any technical ability, especially for managing their cloud resources. Besides of that, Atlantic.net with its click system will make the user more comfortable.
The main objective of improving this is to make customer more efficiently utilize its robust functionality. Provisioning not only the hardware, software, and platforms but also the new servers, deleting existing servers, and to the most importantly is to now be able to handle the turning power on and off by a few lines code makes every programmer just become more productive. Productivity might be what all programmers love, since it is already in their blood. Making program to be used and enjoyed by as many users as possible and watching it significantly
Can online networking sites, such as Facebook and MySpace, help new students settle into university social and academic life and minimise the chance of them withdrawing from their courses?
Researchers at the University of Leicester are now looking for first-year University of Leicester students who use Facebook to help their pioneering research into this issue.
They should not be too difficult to recruit. Student use of the online networking site Facebook is running at a phenomenal level, with almost 10,000 present and past students and staff participating.
Currently, 95 per cent of 16-18 year olds intending to go to university are using social networking sites like Facebook and MySpace.
“Yet we know little about how this phenomenon impacts on the student experience and, in particular, if and how it helps them integrate into university life,” commented Jane Wellens, Education Developer in the University of Leicester’s Staff Development Centre.
“The expectations and online experience of the latest and next generations of students requires universities to think carefully about how, and whether, to use these new technologies and meeting spaces to enhance the social aspects of student integration into university life.”
Dr Wellens is working with Dr Clare Madge, of the Department of Geography, Tristram
If you have read other HowStuffWorks articles on networking or the Internet, then you know that a typical network consists of:
- nodes (computers)
- a connecting medium (wired or wireless)
- specialized network equipment likerouters or hubs.
In the case of the Internet, all of these pieces work together to allow your computer to send information to another computer that could be on the other side of the world!
Switches are another fundamental part of many networks because they speed things up. Switches allow different nodes(a network connection point, typically a computer) of a network to communicate directly with one another in a smooth and efficient manner.
There are many different types of switches and networks. Switches that provide a separate connection for each node in a company’s internal network are called LAN switches. Essentially, a LAN switch creates a series of instant networks that contain only the two devices communicating with each other at that particular moment. In this article, we will focus on Ethernet networks that use LAN switches. You will learn what a LAN switch is and how transparent bridging works, as well as about VLANs, trunking and spanning trees.
Here are some of the fundamental parts of a network:
Online social networking generates vast quantities of data that might be useful to the service providers, advertising agencies, and even the users themselves. Writing in the International Journal of Communication Networks and Distributed Systemsthis month, researchers in India describe an approach to establishing new connections in a network using what they refer to as a “firefly swarm approach”
Ebin Deni Raj and Dhinesh Babu of the School of Information Technology and Engineering, VIT University, in Tamil Nadu, explain that the emergence of social computing, especially in the face of the advent of cloud computing, opens up new ways to extract, analyze and use big data from online networks.
The essence of social computing is community, collaboration and connectivity, but analyzing the three C’s is key to converting data and information into knowledge that might predict trends and help provider and user alike as well as third-parties, such as advertisers. Of course there are hundreds of social networking sites, some more well used and subscribed to than others. Moreover, today’s trendy online haunt can soon become yesterday’s virtual ghost town as has been well-documented by pundits and the technology media over the years.
Raj and Babu suggest that their work can
In the online struggle for network security, Kansas State University cybersecurity experts are adding an ally to the security force: the computer network itself.
Scott DeLoach, professor of computing and information sciences, and Xinming “Simon” Ou, associate professor of computing and information sciences, are researching the feasibility of building a computer network that could protect itself against online attackers by automatically changing its setup and configuration.
DeLoach and Ou were recently awarded a five-year grant of more than $1 million from the Air Force Office of Scientific Research to fund the study “Understanding and quantifying the impact of moving target defenses on computer networks.” The study, which began in April, will be the first to document whether this type of adaptive cybersecurity, called moving-target defense, can be effective. If it can work, researchers will determine if the benefits of creating a moving-target defense system outweigh the overhead and resources needed to build it.
Helping Ou and DeLoach in their investigation and research are Kansas State University students Rui Zhuang and Su Zhang, both doctoral candidates in computing and information sciences from China, and Alexandru Bardas, doctoral student in computing and information sciences from Romania.
As the study progresses the computer scientists
A way to filter out denial of service attacks on computer networks, including cloud computing systems, could significantly improve security on government, commercial, and educational systems. Such a filter is reported in the Int. J. Information and Computer Security by researchers from Auburn University in Alabama.
Denial of Service (DoS) and distributed Denial of Service (DDoS) attacks involve an attempt to make a computer resource unavailable to its intended users. This may simply be for malicious purposes as is often the case when big commercial or famous web sites undergo a DDoS attack. However, it is also possible to exploit the system’s response to such an attack to break system firewalls, access virtual private networks, and to access other private resources. A DoS attack can also be used to affect a complete network or even a whole section of the Internet.
Commonly, attack involves simply saturating the target machine with external internet requests. In the case of a DDoS attack the perpetrator recruits other unwitting computers into a network and uses a multitude of machines to mount the attack. The result is that the resource, whether it is a website, an email server, or a database, cannot respond to
A team of computer scientists at the University of Pennsylvania investigating the political, social and economic struggle between individual self-interest and the need to build a consensus have learned that, depending only on the structure of the network of participants, they can engineer surprising experimental results.
For example, depending solely on the ability of individuals to interact in a network, as well as the number of connections they have to other participants and other structural properties, there are networks that generate the global adoption of minority viewpoints. In addition, the team demonstrated, individuals with extreme behaviors, or a greater awareness of the incentives of others, may actually improve the collective performance of the group. Put simply, stubbornness or extremism may pay off when it comes to social welfare.
Michael Kearns, professor in the Department of Computer and Information Science at Penn, demonstrated in 81 separate experiments that network structure alone can affect outcomes, relationships and behavior.
Kearns’ study, published online in the current Proceedings of the National Academy of Science, builds on ongoing network science research funded by the National Science Foundation and the Multidisciplinary University Research Initiative of the Office of Naval Research since 2005. The overarching goal of
If you are reading this article, you are most likely connected to the Internet and viewing it at the HowStuffWorks Web site. There’s a very good chance that you are using Network Address Translation (NAT) right now.
The Internet has grown larger than anyone ever imagined it could be. Although the exact size is unknown, the current estimate is that there are about 100 million hosts and more than 350 million users actively on the Internet. That is more than the entire population of the United States! In fact, the rate of growth has been such that the Internet is effectively doubling in size each year.
So what does the size of the Internet have to do with NAT? Everything! For a computer to communicate with other computers and Web servers on the Internet, it must have an IP address. An IP address (IP stands for Internet Protocol) is a unique 32-bit number that identifies the location of your computer on a network. Basically, it works like your street address — as a way to find out exactly where you are and deliver information to you.
When IP addressing first came out, everyone thought that there were plenty of addresses to cover any
Once, home networks were primarily the realm of technophiles — most families either didn’t need or couldn’t afford more than one computer. But now, in addition to using computers for e-mail, people use them for schoolwork, shopping, instant messaging, downloading music and videos, and playing games. For many families, one computer is no longer enough to go around. In a household with multiple computers, a home network often becomes a necessity rather than a technical toy.
A home network is simply a method of allowing computers to communicate with one another. If you have two or more computers in your home, a network can let them share:
- Files and documents
- An Internet connection
- Printers, print servers and scanners
- Stereos, TVs and game systems
- CD burners
The different network types use different hardware, but they all have the same essential components:
- More than one computer
- Hardware (such as a router) and software (either built in to the operating system or as a separate application) to coordinate the exchange of information
- A path for the information to follow from one computer to another
If you’re thinking of networking the computers in your home, you have several options to explore.
Building a Home Network
The two most popular home network types arewireless and Ethernet networks.
Have you ever wondered about the mechanisms that delivered this page to you? Chances are you are sitting at a computer right now, viewing this page in a browser. So, when you clicked on the link for this page, or typed in its URL (uniform resource locator), what happened behind the scenes to bring this page onto your screen?
If you’ve ever been curious about the process, or have ever wanted to know some of the specific mechanisms that allow you to surf the Internet, then read on. In this article, you will learn how Web servers bring pages into your home, school or office. Let’s get started!
The Basic Process
Let’s say that you are sitting at your computer, surfing the Web, and you get a call from a friend who says, “I just read a great article! Type in this URL and check it out. It’s at http://www.howstuffworks.com/web-server.htm.” So you type that URL into your browser and press return. And magically, no matter where in the world that URL lives, the page pops up on your screen.
At the most basic level possible, the following diagram shows the steps that brought that page to your screen:
Your browser formed a connection to
When they make their first public demonstration of tele-immersion at this week’s Super Computing 2002 conference in Baltimore, computer scientists will also attain another first: a “network computer” that processes data at a location far removed from either input or output.
While the tele-immersion system will gather and display information in side-by-side booths at the Baltimore Convention Center, actual data processing will occur some 250 miles away at the Pittsburgh Supercomputing Center. Previous demonstrations of tele-immersion, a next-generation type of ultra-realistic videoconferencing that draws upon Internet2 and technology similar to that used in 3D movies, have relied upon local computing power at the University of Pennsylvania and other participating institutions.
“Shifting the computing from 10 processors at Penn to 1,240 parallel machines based in Pittsburgh will speed data processing 75-fold, turning tele-immersion into a true real-time technology,” said Kostas Daniilidis, an assistant professor of computer and information science at Penn. “It now takes our tele-immersion system roughly 15 seconds to scan, process and display the entire volume of a typical room. With help from the Pittsburgh Supercomputing Center, that time will shrink to 200 milliseconds.”
This week’s tele-immersion demonstration in Baltimore, presented by scientists from Penn and the University of North Carolina at
It turns out that everything you do on the Internet involves packets. For example, every Web page that you receive comes as a series of packets, and every e-mail you send leaves as a series of packets. Networks that ship data around in small packets are called packet switched networks.
On the Internet, the network breaks an e-mail message into parts of a certain size in bytes. These are the packets. Each packet carries the information that will help it get to its destination — the sender’s IP address, the intended receiver’s IP address, something that tells the network how many packets this e-mail message has been broken into and the number of this particular packet. The packets carry the data in the protocols that the Internet uses: Transmission Control Protocol/Internet Protocol (TCP/IP). Each packet contains part of the body of your message. A typical packet contains perhaps 1,000 or 1,500 bytes.
Each packet is then sent off to its destination by the best available route — a route that might be taken by all the other packets in the message or by none of the other packets in the message. This makes the network more efficient. First, the network can
By exploiting the full computational power of the Japanese supercomputer, K Computer, researchers from the RIKEN HPCI Program for Computational Life Sciences, the Okinawa Institute of Technology Graduate University (OIST) in Japan and Forschungszentrum Jülich in Germany have carried out the largest general neuronal network simulation to date.
The simulation was made possible by the development of advanced novel data structures for the simulation software NEST. The relevance of the achievement for neuroscience lies in the fact that NEST is open-source software freely available to every scientist in the world.
Using NEST, the team, led by Markus Diesmann in collaboration with Abigail Morrison both now with the Institute of Neuroscience and Medicine at Jülich, succeeded in simulating a network consisting of 1.73 billion nerve cells connected by 10.4 trillion synapses. To realize this feat, the program recruited 82,944 processors of the K Computer. The process took 40 minutes, to complete the simulation of 1 second of neuronal network activity in real, biological, time.
Although the simulated network is huge, it only represents 1% of the neuronal network in the brain. The nerve cells were randomly connected and the simulation itself was not supposed to provide new insight into the brain
What a difference four letters make! Intranet isn’t just a misspelling of Internet. According to the Merriam-Webster online dictionary, the prefix “intra-” is Latin for “within.” Which makes sense because an intranet works exactly like the Internet, except it’s a network confined within a company, school, government or organization.
For example, HowStuffWorks.com is a Web site hosted by a Web server connected to the Internet. Anyone in the world with Internet access can visit HowStuffWorks.com and read articles like this one.
Let’s pretend that the employees of HowStuffWorks use another Web site called HSWIntranet.com to post events on a community calendar, read messages from founder Marshall Brain and access the company phone directory. HSWIntranet is hosted on a Web server located in the HowStuffWorks headquarters in Atlanta and is connected only to the company’s local area network (LAN). Only employees connected to the LAN via a special network password can access the company intranet. HSWIntranet.com isn’t an Internet site; it’s an intranet site.
Both the Internet and an intranet operate over a communications standard called TCP/IP (transmission control protocol/Internet protocol) that connects hosts to users over a network. Both the Internet and an intranet use Web pages to display information on users’ computers.
The Internet is one of the 20th century’s greatest communications developments. It allows people around the world to send e-mail to one another in a matter of seconds, and it lets you read, among other things, the articles on HowStuffWorks.com.
We’re all used to seeing the various parts of the Internet that come into our homes and offices — theWeb pages, e-mail messages and downloaded files that make the Internet a dynamic and valuable medium. But none of these parts would ever make it to your computer without a piece of the Internet that you’ve probably never seen. In fact, most people have never stood “face to machine” with the technology most responsible for allowing the Internet to exist at all: the router.
When you send e-mail to a friend on the other side of the country, how does the message know to end up on your friend’s computer, rather than on one of the millions of other computers in the world? Much of the work to get a message from one computer to another is done by routers, because they’re the crucial devices that let messages flow between networks, rather than within networks.
Let’s look at what a very simple router might