Network fore File Sharing

A Simple Computer Network for File Sharing

Simple Network with Two Computers Connected via a Cable

This diagram illustrates the simplest possible kind of computer network. In a simple network, two computers (or other networkable devices) make a direct connection with each and communicate across a wire or cable. Simple networks like this have existed for decades. A common use for these networks is file sha

Local Area Network

A Local Area Network (LAN) with Printer

Local Area Network (LAN) with Printer

This diagram illustrates a typical local area network (LAN) environment. Local area networks often feature a group of computers located in a home, school, or part of an office building. Like a simple network, computers on a LAN share files and printers. Computers on one LAN can also can share connections with other LANs and with the Internet.

Wide Area Networks

A Hypothetical Wide Area Network

This diagram illustrates a hypothetical  wide area network (WAN) configuration that joins LANs in three metropolitan locations. Wide area networks cover a large geographic area like a city, a country or multiple countries. WANs normally connect multiple LANs and other smaller-scale area networks. WANs are built by large telecommunication companies and other corporations using highly-specialized equipment not found in consumer stores. The Internet is an example of a WAN that joins local and metropolitan area networks across most of the world.

Wire Computer Network

Wired Computer Networks

Wired Computer Networks

This diagram illustrates several common forms of wiring in computer networks. In many homes, twisted-pair Ethernet cables are often used to connect computers. Phone or cable TV lines in turn connect the home LAN to the Internet Service Provider (ISP). ISPs, larger schools and businesses often stack their computer equipment in racks (as shown), and they use a mix of different kinds of cable to join this equipment to LANs and to the Internet. Much of the Internet uses high-speed fiber optic cable to send traffic long distances underground, but twisted pair and coaxial cable can also be used for leased lines and in

Wireless Computer Network

Wireless Computer Networks

Wireless Computer Networks

This diagram illustrates several common forms of wireless computer networks. Wi-Fi is the standard technology for building wireless home networks and other LANs. Businesses and communities also use the same Wi-Fi technology to set up public wireless hotspots. Next, Bluetooth networks allow handhelds, cell phones and other other peripheral devices to communicate over short ranges. Finally, cellular network technologies including WiMax and LTE support both voice and data communications over mobile phones.

OSI Model of Computer

The OSI Model of Computer Networks

The OSI Model for Computer Networks

This diagram illustrates the Open Systems Interconnection (OSI) model. OSI is primarily used today as a teaching tool. It conceptually devices a network into seven layers in a logical progression. The lower layers deal with electrical signals, chunks of binary data, and routing of these data across networks. Higher levels cover network requests and responses, representation of data, and network protocols as seen from a user's point of view. The OSI model was originally conceived as a standard architecture for building network systems and indeed, many popular network technologies today reflect the layered design of OSI.

Network

 Visual Index of Computer Networking Topics

This guide to networks breaks down the topic into a series of visual exhibits. Each page features one key concept or element of wireless and computer networking.

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Enter Gallery

Simple Network for Sharing.

A Simple Computer Network for File Sharing

Simple Network with Two Computers Connected via a Cable

This diagram illustrates the simplest possible kind of computer network. In a simple network, two computers (or other networkable devices) make a direct connection with each and communicate across a wire or cable. Simple networks like this have existed for decades. A common use for these networks is file sharing.

 

Gateway

Gateway

Definition: A network gateway is an internetworking system capable of joining together two networks that use different base protocols. A network gateway can be implemented completely in software, completely in hardware, or as a combination of both. Depending on the types of protocols they support, network gateways can operate at any level of the OSI model.

Because a network gateway, by definition, appears at the edge of a network, related capabilities like firewalls tend to be integrated with it. On home networks, a broadband router typically serves as the network gateway although ordinary computers can also be configured to perform equivalent functions.

firewall

Definition: A network firewall protects a computer network from unauthorized access. Network firewalls may be hardware devices, software programs, or a combination of the two.

Network firewalls guard an internal computer network (home, school, business intranet) against malicious access from the outside. Network firewalls may also be configured to limit access to the outside from internal users.

Network Firewalls and Broadband Routers

Many home network router products include built-in firewall support. The administrative interface of these routers include configuration options for the firewall. Router firewalls can be turned off (disabled), or they can be set to filter certain types of network traffic through so-called firewall rules.

Network Firewalls and Proxy Servers

Another common form of network firewall is a proxy server. Proxy servers act as an intermediary between internal computers and external networks by receiving and selectively blocking data packets at the network boundary. These network firewalls also provide an extra measure of safety by hiding internal LAN addresses from the outside Internet. In a proxy server firewall environment, network requests from multiple clients appear to the outsider as all coming from the same proxy server address.

OSI Model

OSI Model - Open Systems Interconnection model

Definition: The OSI model defines internetworking in terms of a vertical stack of seven layers. The upper layers of the OSI model represent software that implements network services like encryption and connection management. The lower layers of the OSI model implement more primitive, hardware-oriented functions like routing, addressing, and flow control.

In the OSI model, data communication starts with the top layer at the sending side, travels down the OSI model stack to the bottom layer, then traveses the network connection to the bottom layer on the receiving side, and up its OSI model stack.

The OSI model was introduced in 1984. Although it was designed to be an abstract model, the OSI model remains a practical framework for today's key network technologies like Ethernet and protocols like IP.

Also Known As: Open Systems Interconnection (OSI) reference model, OSI seven layer model

Examples:

Internet Protocol (IP) corresponds to the Network layer of the OSI model, layer three. TCP and UDP correspond to OSI model layer four, the Transport layer. Lower layers of the OSI model are represented by technologies like Ethernet. Higher layers of the OSI model are represented by application protocols like TCP and UDP.

broadband router

Definition: A broadband router combines the features of a traditional network switch, a firewall, and a DHCP server. Broadband routers are designed for convenience in setting up home networks, particularly for homes with high-speed cable modem or DSL Internet service. A broadband router supports file sharing, Internet connection sharing, and home LAN gaming.

A broadband router follow the Ethernet standard for home networking. Traditional broadband routers required Ethernet cables be run between the router, the broadband modem, and each computer on the home LAN. The newer wireless routers also support broadband Internet access and the Ethernet standard without the need for cabling.

Several manufacturers offer broadband router products to the consumer. Features that differentiate broadband router products include the number and type of ports available on the unit for cabling computers, external modems, or other network devices.

LAN

LAN - Local Area Network

Definition: A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LANs, and to the Internet or other WAN.

Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, network adapters, and hubs. Wireless LAN and other more advanced LAN hardware options also exist.

Specialized operating system software may be used to configure a local area network. For example, most flavors of Microsoft Windows provide a software package called Internet Connection Sharing (ICS) that supports controlled access to LAN resources.

The term LAN party refers to a multiplayer gaming event where participants bring their own computers and build a temporary LAN.

ICS

ICS - Internet Connection Sharing

Definition: ICS allows a local network of Windows computers to share a single Internet connection. Microsoft developed ICS as part of Windows 98 Second Edition. The feature has been included as part of all subsequent Windows releases, but it is not available as a separate installable program.

ICS follows a client/server model. To set up ICS, one computer must be chosen as the server. The designated computer must support two network interfaces, one directly connected to the Internet and the other connected to the remainder of the LAN. In a traditional home dial-up network, for example, the server computer is directly connected to the modem.

When configured through Windows, the ICS server behaves as a NAT router, directing messages on behalf of multiple computers. ICS incorporates a DHCP server that allows clients to obtain their local addresses automatically rather than needing to be set manually.

Compared to hardware routers, ICS has the advantage of being included with the operating system so no additional purchase is required. On the other hand, ICS lacks many of the configuration options that hardware routers possess.

Starting the Computer

Starting the Computer in Safe Mode

1. Restart the computer.
• If the computer is not a member of a domain:
1. From the Start menu, click Turn Off Computer.
2. In the Turn Off Computer dialog box, click Restart.
• If the computer is a member of a domain:
1. From the Start menu, click Shut Down.
2. In the What do you want the computer to do list, click Restart, and then click OK.

Note: A domain is a group of computers that are part of a network and share a common directory database.

2. As the computer restarts, begin pressing the F8 key after the Gateway BIOS logo appears until the Windows Advanced Options Menu screen appears.
3. On the Windows Advanced Options Menu screen, use the arrow keys to select Safe Mode, and then press the ENTER key.

After logging on to Windows XP Safe mode, in the Desktop dialog box, click Ye