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The Internet – The Largest Network in the World

admin — Wed, 03 Mar 2010 03:48:34 +0000

Computer engineers have been finding ways to connect computers and their devices together in different ways. Computer networking has come hand in hand with other bodies of knowledge such as telecommunications, information technology, and computer engineering. So many things have been made possible through computer networking. It has helped people live easier lives in many ways through personal area network, local area network, metropolitan area network, and wide area network.

One great example of a wide area network is the champion of all networks, the Internet. It is the biggest network in the world, and billions of data (maybe even trillions) is being transferred everyday. So much information is exchanged and it has practically changed the way we live our lives.

Education online

The usual way to get your education is to enroll in a school, and go to your classes on a fixed schedule. Nowadays, we can actually get a college and master’s degree through the Internet. A lot of reputable universities now offer their courses online because they understand how hard it is for some students to juggle a job and their schooling. Depending on the program, you can have your own schedule, and usually you’d just have to submit work on or before a particular deadline. At times, you’d have real time chatting with you professor and “classmates”, sometimes even with a webcam. What’s great about this is that you no longer have to go through the hassle of commuting. The good news is that companies have been accepting a lot of applicants with this sort of education but there are still some that are overly traditional.

Video games galore

What started out as simple 2 dimension games is now a multi-billion dollar industry, and has spawned a new way of social interaction. Because of the Internet, gamers are now able to interact with people from across the globe, and play the same game at the same time. This is great because video games were once viewed as an anti-social activity. This is no longer true and now gamers not only get to play the game together, but are able to chat and make new friends as well. Internet gaming has also created a new gaming genre called “massively multiplayer online role-playing games” or MMORPGs. This is a supercharged type of RPG where thousands of players get to play together in a particular game at the same time.

Social Networking

A lot of websites nowadays allow people to interact and socialize with each other with their different tools and services. Some of them are focused on dating, where users can create their own profile and indicate their particular tastes. Other websites are dedicated to people uploading pictures and sharing them with other users as well. This has been a great way of connecting with long lost friends, and making new ones as well.

It’s great that computer networking has helped in bringing us the Internet. With it, life has become more convenient, and we can learn so many new things everyday just by connecting to it. With the Internet, there are certainly more new things to come.

By: Benedict Yossarian

Computer Network Training

admin — Mon, 22 Feb 2010 13:18:06 +0000

Computer network training is one of the latest gateways to jump into the competitive IT world. Network is a media for computers to communicate with each other by sending files, instant messages and other information. This is accomplished through LAN (Local Area Network) and WAN (Wide Area Network). Nowadays, many companies use networks of computers to run their operations smoothly. So, computer networking is a good job option. Basically, there are two main networks, namely Microsoft and Novell.

Specialized degree and certificate network training programs are available through several institutions, schools and online coaching. Many schools conduct training courses as part of regular programs and vocation courses. Some of these schools have labs outside the classroom that students can attend during designated hours. Online training courses allow students to take their courses anytime, anywhere. In addition, you can purchase training courses individually or bundled, available on CD-ROM. Each regular training program extends from six months to one year.

Each networking training course comprises fundamental programs about the working plans of network, wiring and the types of software installed in computers. Normally, these basic courses run just for a few weeks. Students learn about workstations, servers, their functions, and different types of networking such as client server and peer to peer.

After the fundamental program, the training moves gradually toward the next higher part. In this phase, students can learn about individual systems and their differences. Many schools divide this phase into two operating systems, for Novell and Microsoft. Students can take either one or both. Each operating system course normally extends up to 3 months. But some schools concentrate on one system. Practical procedures such as installing workstation software, installing server software, wiring and finally, making a simple computer network are involved.

The students are prepared for the certification exams. The examination has a number of practice tests. Most centers allow their students to continue the training until they have passed the exams.

By: Ken Marlborough

Wide Area Network (WAN)

admin — Mon, 11 Jan 2010 07:40:52 +0000

Types and Characteristics of WANs

What is a WAN?

There are two prevailing definitions of a Wide Area Network (WAN). The book definition of a WAN is a network that spans large geographical locations, usually to interconnect multiple Local Area Networks (LANs). The practical definition of a WAN is a network that traverses a public network or commercial carrier, using one of several WAN technologies

What are its Main Components?

The main components for a WAN are routers, switches and modems. These components are described below in the hardware section.

CPE – Devices on the subscriber premises are called customer premises equipment (CPE).
The subscriber owns the CPE or leases the CPE from the service provider. A copper or fiber cable connects the CPE to the service provider’s nearest exchange or central office. This cabling is often called the local loop, or “last-mile”.

DTE/DCE – Devices that put data on the local loop are called data circuit-terminating equipment, or data communications equipment (DCE). The customer devices that pass the data to the DCE are called data terminal equipment (DTE). The DCE primarily provides an interface for the DTE into the communication link on the WAN cloud.

Hardware

In a WAN you will need various types of hardware components for it to function. The typical items of hardware that you will need in a WAN are:

Router – An electronic device that connects a local area network (LAN) to a wide area network (WAN) and handles the task of routing messages between the two networks. Operates at layer 3, and makes decisions using IP addresses.

Switch – A switch is a network device that selects a path or circuit for sending a unit of data to its next destination. Operates at layer 2, and uses MAC addresses to send data to correct destination.

Modem – Short for modulator/demodulator, a modem enables a computer to communicate with other computers over telephone lines. Operates at layer 1, where signals are converted from digital to analogue and vice versa for transmission and receiving.

Wan Standards

WANs operate within the OSI model using layer 1 and layer 2 levels. The data link layer and the physical layer. The physical layer protocols describe how to provide electrical, mechanical and functional connections to the services provided by the ISP. The data link layer defines how data is encapsulated for transmission to remote sites.

Encapsulation

Encapsulation is the wrapping of data in a particular protocol header. Remember that WANs operate at the physical layer and the data link layer of the osi model and that higher layer protocols such as IP are encapsulated when sent across the WAN link. Serial interfaces support a wide range of WAN encapsulation types, which must be manually specified. These types include SDLC, PPP, Frame delay etc. Regardless of WAN encapsulation used it must be identical on both sides of the point to point link.

Packet and Circuit Switching

Circuit switching and packet switching are both used in high-capacity networks.
The majority of switched networks today get data across the network
through packet switching.

Circuit-switching is more reliable than packet-switching. Circuit switching is old and expensive, packet switching is more modern.

General Routing Issues

What is a Routing Protocol?

A routing protocol is a protocol that specifies how routers communicate and exchange information on a network. Each router has prior knowledge of its immediate neighbours and knows the structure of the network topology. The routers know this because the routing protocol shares this information.

Protocol

RIP (Routing Information Protocol) was one of the most commonly uses protocols on internal networks. Routers use RIP to dynamically adapt changes to the network connections and communicate information about which networks routers can reach and the distance between them. RIP is sometimes said to stand for Rest in Pieces in reference to the reputation that RIP has for breaking unexpectedly and rendering a network unable to function.

Routing Algorithms

Distance Vector

This type of routing protocol requires that each router simply inform its neighbours of its routing table. The distance vector protocol is also known as the bellman-ford algorithm.

Link State

This type of routing protocol requires that each router maintain a partial map of the network. The link state algorithm is also know as Dijkstra’s algorithm.

IGRP

IGRP is a type of distance vector routing protocol invented by cisco used to exchange routing data in a autonomous system. Distance vector protocols measure distances and compare routes. Routers that use distance vector must send all or a portion of their routing table in a routing update message at regular intervals to each neighbour router.

Addressing and Routing

What does routing mean?

Routing is the process of deciding how to move packets from one network to another.
The directions also known as routes can be learned by a router using a routing protocol then the information is passed from router to router along the route of the destination.

IP Address’s

Every machine connected to the internet is assigned an IP address. An example of an IP address would be 192.168.0.1. IP addresses are displayed in decimal format to make it easier for humans to understand but computers communicate in binary form. The four numbers that separate an IP address are called Octets. Each position consists of eight bits. When added to together you get 32 bit address. The purpose of each octet in an IP address is to create classes of IP addresses that can be assigned within a network. There are three main classes that we deal with Class A, B and C. The octets of an IP address are split into two parts Network and Host. In a class A address the first octet is the network portion, this determines which network the computer belongs to, the last octets of the address are the hosts that belong to the network.

Sub netting

Sub netting allows you to create multiple networks within a class A, B or C address. The subnet address is the address used by your LAN. In a Class C network address you would have a subnet mask of 255.255.255.0. A subnet mask identifies which portion is network and which is host. For example 192.168.6.15 the first octet three octets are the Network address and the last octet being the host(Workstation). It is important to subnet a network because gateways need to forward packets to other LANS. By giving each NIC on the gateway an IP address and a Subnet mask it allows the gateways to route packets from LAN to LAN. Once the packet arrives at its destination, the gateway then uses the bits of the subnet portion of the IP address to decide which LAN to send the packets.

Circuit Switched Leased Lines

A circuit switched network is one that establishes a dedicated circuit (or channel) between nodes and terminals before the users may communicate. Here are some terminologies associated with a Circuit switched network.

Frame relay is a telecommunication service designed for cost-efficient data transmission between local area networks (LANs)

Basic rate interference is a service used by small business for internet connectivity. An ISDN BRI provides two 64 Kbps digital channels to the user.
Primary rate interface (PRI) is a telecommunications standard for carrying voice and data transmissions between two locations
All data and voice channels are ISDN and operate at 64kbit/s

Packet Switching

http://www.raduniversity.com/networks/2004/PacketSwitching/main.htm – _Toc80455261

Packet switching refers to protocols in which messages are broken up into small packets before they are sent. Each packet is then transmitted over the Internet. At the destination the packets are reassembled into the original message. Packet switching main difference from Circuit Switching is that that the communication lines are not dedicated to passing messages from the source to the destination. In Packet Switching, different messages can use the same network resources within the same time period.

http://en.wikipedia.org/wiki/Asynchronous_Transfer_Mode

Asynchronous Transfer Mode (ATM) is a cell relay, packet switching network and protocolwhich encodes data into small fixed-sized cells.

ISDN is used to carry voice, data, video and images across a telephone network. ISDN stands for integrated services Digital Network. Isdn also provides users with a 128kbps bandwidth. This is done through frame relay. Frame relay complements and provides a service between ISDN, which offers bandwidth at 128 Kbps and Asynchronous Transfer Mode which operates in somewhat similar fashion to frame relay but at speeds from 155.520 Mbps or 622.080 Mbps. Frame relay is based on the older X.25 packet switching technology and is used to transmit analogue signals such as telephone conversations.

PSDN stands for packet switched data network and is a data communication network. Packet switched networks do not establish a physical communication signal like the public telephone does (circuit switched network) Packets are sent on a fixed length basis and assigned with a source and a destination address. The packets then rely on the routers to read the address and route the packets through the network.

Mobile and Broadband Services

Digital Subscriber line(DSL) is mainly used to bring high bandwidth connections to homes and small business’s over a copper wire telephone line. This is can only be achieved if you stay within the range of the telephone exchange. DSL offers download rates of up to 6mbps allowing continuous transmission of video, audio and 3D effects. DSL is set to replace ISDN and compete with the cable modem in providing multimedia to homes. DSL works by connecting your telephone line to the telephone office over copper wires that are twisted together.

Asymmetric Digital Subscribers Line is most commonly used for home users. It provides a high download speed but a lower upload speed. Using ADSL, up to 6.1 megabits per second of data can be sent downstream and up to 640 Kbps upstream.

http://en.wikipedia.org/wiki/Symmetric_Digital_Subscriber_Line

Symmetric Digital Subscriber Line is a digital subcriber line which runs over one pair of copper wires. The main difference between ADSL and SDSL is the difference in upload and download speeds. SDSL allows the same upstream data rate and downstream data rate as ADSL upstream can be very slow.

[http://searchnetworking.techtarget.com/sDefinition/0],,sid7_gci558545,00.html

HDSL High bit-rate Digital Subscriber Line, one of the earliest forms of DSL, is used for wideband digital transmission within a corporate site and between the telephone company and a customer. The main characteristic of HDSL is that provides equal bandwidth in both directions.

IDSL is a system in which data is transmitted at 128 Kbps on a regular copper telephone line from a user to a destination using digital transmission.

The Local Loop enables operators to connect directly to the consumer via copper local loops and then add their own equipment to offer broadband and other services. This process involves operators accessing local exchange buildings to connect to a network of copper lines which connect them to homes and businesses. BT is an Example of a Local Exchange. The local loop connecting the telephone exchange to most subscribers is capable of carrying frequencies well beyond the 3.4 kHz upper limit.

Benefits of using DSL

DSL can provide virtually instantaneous transmission of voice, data and video over ordinary copper phone lines. A DSL connection can eliminate delays when waiting to download information and graphics from the Internet. It provides users with a cost effective high speed Internet connection. Another benefit is that a DSL connection is always on-line (like a LAN connection) with no waiting time for dialling or connecting.

There are now more than 10 million broadband connections in the UK. By December 2005 there were 9.792 million broadband connections in the UK and the average broadband take up rate during the three months to December was more than 70,000 per week.

By: Chris Michael Jones

Discovering Your Local Area Network

admin — Sat, 09 Jan 2010 22:03:48 +0000

In the late 1960’s as large college universities and several research labs gained an ever increasing amount of computers, the need for interconnections that worked at high-speed was great, and the pressure was on. It was not until the mid 1970’s that an answer to the demand was created, they called it LAN.

LAN stands for Local-Area Network, with the ability to cover small areas, such as a home or office or group of buildings (schools, warehouse, etc.), LANs have higher data-transfer rates, smaller range and do not require licensed telecommunication lines as opposed to WAN (Wide-Area Network). ARCNET and Token Ring were two LANs that were widely used in the past. Ethernet and Wi-Fi are two of today’s most common LANs.

A LAN is an important component to gamers. By setting up a LAN, gamers can link together their computers and play with or against their friends. Games, such as “Diablo II” and “S.O.C.O.M.”, allows gamers to cooperate together in a team while either on line or while their computers are connected by LAN.Games, such as “Unreal Tournament” and “Starcraft”, allow gamers connected by the internet or a LAN to work as a team or to compete against each other.computers are usually linked by what is known as a Cat-5 cable to a HUB; and the HUB acts like a mediator. The Cat-5 cable connects to the back of the computer through the Ethernet port on the Network card, network adapter, LAN adapter or NIC (Network Interface Card). A network card operates on both the physical layer and the data link layer; it allows a low-level addressing system, using Mac Addresses, also known as an IP address, and physical access to the networking medium (the HUB). Not all LANs are the same; some use cables while others are wireless.

While other network technology exists, since the mid 1990’s, the Ethernet network card has been leading the crowd, due to low cost and easy integration and use. A unique 48-bit serial number is on every Ethernet network card, stored in the ROM; the serial number is your computers Mac address. The Mac address for every computer must be unique; otherwise only one computer with a given Mac address could be on line and connected to the LAN at a time. The Institute of Electrical and Electronics Engineers is responsible for each unique Mac address getting assigned to vendors of interface controllers; this is so no two network cards share the same Mac address.

At one point network cards were expansion cards that had to be plugged into the motherboard. Most new computers have the network card built into the motherboard; some may even have two ports built in so the computer can be connected to multiple networks. Some companies have started using optical fiber instead of Cat-5 cables or USB cords, because optical fiber is immune to electromagnetic interference. Optical fibers are made of glass or plastic, instead of metal, and carry light along their full length. The electrical signals sent along the optical fiber degrade less during transfer than signals sent along metal wires (Cat-5 cables and USB cords).

By: Victor Epand

What Is The Real Difference Between LAN And WAN Computer Network Infrastructures?

admin — Fri, 08 Jan 2010 12:04:10 +0000

Although a business shouldn’t be confused on what the differences are between Local Area Network (LAN) and Wide Area Network (WAN) … too often those entrusted with finding a bandwidth solution for their business aren’t clear on these basic tenets of overall computer network infrastructure. If not completely understood it affects the quality and accuracy of the final decision. So … it’s important to get it right.

So …. in the interest of clarity here’s the real differences between LAN and WAN:

LAN – A local area network (LAN) is a computer network covering a local area, like a home, office, or group of buildings in close proximity to each other. Current LANs are most likely to be based on switched IEEE 802.3 Ethernet, or on Wi-Fi technology running at 10, 100 or 1,000 Mbit.

In general a local area network is made up of devices in local proximity to each other and has finite distance limitations. The LAN can be either wired or wireless but is only at a single location.

WAN – A wide area network or WAN is a computer network covering a broad geographical area. Contrast with personal area networks (PANs), metropolitan area networks (MANs) or local area networks (LANs) that are usually limited to a room, building or campus. The largest and most well-known example of a WAN is the Internet.

A wide area network (WAN) is comprised of multiple LANs connected to each other across distances. And example would be a corporate office connected to each of its satellite offices. This method of interconnection is handled via a third-party carrier — i.e. Qwest provides the wiring connecting two locations together.

WANs are used to connect local area networks (LANs) together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization’s LAN to the Internet. WANs are most often built using leased lines. At each end of the leased line, a router connects to the LAN on one side and a hub within the WAN on the other. Leased lines can be very expensive. Instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods. Network protocols including TCP deliver transport and addressing functions. Protocols including Packet over SONET, MPLS, ATM and Frame relay are often used by service providers to deliver the links that are used in WANs. X.25 was an important early WAN protocol, and is often considered to be the “grandfather” of Frame Relay as many of the underlying protocols and functions of X.25 are still in use today (with upgrades) by Frame Relay.

For professional help in finding just the right LAN or WAN solution for your business applications …. use the no cost assistance available through DS3-Bandwidth.com.

By: Michael Lemm

Computer Network – Comprehensive View – Part 2

admin — Fri, 13 Nov 2009 21:14:17 +0000

Wireless networks located in multiple categories, depending on the size of the physical area that can be covered by network.

The following types of wireless network meet the needs of multiple users:

* Wireless personal – Area network (PAN).

* Wireless Local Area network (LAN).

* Wireless Metropolitan-Area network (MAN).

* Wireless Wide – Area network (MAN).

This is using the expansion all major cables for wired networks (such as LAN or WAN) used for years before it enters the wireless network.

Each type of wireless network has the advantages of complementary meet multiple requirements. The following paragraphs explore each type of wireless networks in a concise manner.

Wireless networks (PANS):

The area of wireless networks is a relatively short (up to 50 feet) and most of their effectiveness to meet the needs of a small room or in the cargo area. PANS networks is the performance of the average of data rate of up to (2MBPS). Imperatives followed these advantages for the replacement of cables in many cases.

PAN wireless network includes a person synchronize personal PDA with his laptop computer or personal computer. In a similar, PAN wireless network can provide radio communication to the printer. The advantage of the abolition of knots in the wire when using this type of computer is very useful, where the initial installation of the equipment is easy.

Wireless networks (LANS):

Networks wireless LANs provide high performance within and around office buildings and labs, and homes often have the users in these areas laptop computers, personal computers, PDA screens and processors to support large applications. LANS meet the requirements of communication for these types of computers effectively.

For example, in the work it can be installed the wireless LAN network to provide mobile access to the common applications of laptops. This type of system, the user can, while far from his office, take advantage of network services from the conference rooms and other rooms. That allows staff to be more effective while working away from their offices and more cooperative with each other.

Wireless networks LANS provide the performance levels enable applications to operate smoothly. For example, the wireless network LAN users can easily see e-mail attachments or a large scale video server of the invisible with data rate up to (54 MBPS). Wireless LAN network can meet only networks with the limits of web applications a house or office.

Wireless networks (MAN’S):

MAN’S wireless network includes areas with the size of cities.

Wireless Service Providers (WISPs) Provide wireless networks in cities and remote areas in order to provide homes and firms for wireless communications. Wireless networkings MAN provides the positive benefits and are appropriate when it is impractical to install a traditional wired communications such as (DSL and cable modem). Wireless networks WANS are effective when the right path for the cable systems have made it not possible or too expensive.

Wireless networks (WAN’S):

MAN networks known as mobile wireless applications cover a large area, such as state or continent. Because of the economic side, the operator is able to do remote deployment of the operational infrastructure of the wireless network MAN in order to provide relatively inexpensive long-distance communication for a lot of consumers. It is possible to distribute the costs of such a deployment across multiple users. It provides low fees -subscription.

By: Shrif S Kassem

Virtual Private Network and Network Connections

admin — Fri, 06 Nov 2009 04:02:37 +0000

Network In information technology, a network is a series of points or nodes interconnected by communication paths. Networks can interconnect with other networks and contain subnetworks.

Local Area Network (LAN) A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link. Typically, connected devices share the resources of a single processor or server within a small geographic area (for example, within an office building). Usually, the server has applications and data storage that are shared in common by multiple computer users. A local area network may serve as few as two or three users (for example, in a home network) or as many as thousands of users (for example, in an FDDI network). See also: WAN and MAN

Wide Area Network (WAN) A wide area network (WAN) is a geographically dispersed telecommunications network. The term distinguishes a broader telecommunication structure from a local area network (LAN). A wide area network may be privately owned or rented, but the term usually connotes the inclusion of public (shared user) networks. An intermediate form of network in terms of geography is a metropolitan area network (MAN).

Metropolitan Area Network (MAN) A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN). The term is applied to the interconnection of networks in a city into a single larger network (which may then also offer efficient connection to a wide area network). It is also used to mean the interconnection of several local area networks by bridging them with backbone lines. The latter usage is also sometimes referred to as a campus network.

Network Backbone A backbone is a larger transmission line that carries data gathered from smaller lines that interconnect with it.

Nodes In a network, a node is a connection point, either a redistribution point or an end point for data transmissions. In general, a node has programmed or engineered capability to recognize and process or forward transmissions to other nodes.

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By: Aaron Adams

The Need For Network Security and Maintenance

admin — Thu, 05 Nov 2009 23:41:43 +0000

Why Computers and Networks?

Computers have become a necessity for all types of working environment. No matter what type of work you are doing, computers can help you in maximizing your work efficiency. Due to this fact computers are being used in all types of offices. Some areas like banking, insurance, stock exchange as well as reservation systems completely rely on use of Computers and Internet.

In a computing environment people need inter connectivity of computers to share resources like (files and data). It further helps in use and management of information collected through various nodes. These kinds of network that is being implemented in a particular organization are known as Intranets. Intranet helps in information sharing between different offices of same organization at different locations. It works on LAN (Local Area Network), MAN (Metropolitan Area Network) or WAN (Wide Area Network). There are mainly three ways of implementing different type of networks – wired, wireless or mixed (wired and wireless both as and when required).

Why Internet?

Internet is information superhighway, one of the major and accurate sources of getting information on any topic quickly. It is also used as backbone for implementing Intranet. Company’s websites and email are completely dependent on Internet. In brief, internet is the most important and fastest medium of communication in current hi-tech world.

Network Related Problems

As an end user you must have experienced various types of problems in your network during your work. Due to network downtime organizations have to bear loss of several productive working hours or in turn loss of revenue. Network downtime for your web servers may result unavailability of your website, in that case your potential viewers may not find required information through your website. It may create a negative impact of your company/organization or business

To deal with such problems immediately organizations need network diagnosis and maintenance experts to fix such problems to further reduce loss of productive working hours. However, it is not possible for every organization to hire a fulltime team of networking experts to solve their network issues. They prefer to rely upon network security consultants, who help them whenever needed. It’s a cost-effective alternative for organizations because they don’t have to hire full time professionals for taking care of their network troubleshooting needs.

By: Dan Stratton