Module 2 Part 2 Exercise 18-4-2016

Computer Network

• LAN

LAN stands for Local Area Network, is a group of computers which belongs to the same organisation, and are linked within a small geographic area using a network, and often the same technology - usually ethernet.

• WAN

WAN (Wide Area Network) connects multiple LANs to one another over great geographical distances any network whose communications link cross metropolitan, regional, or national boundaries). The most well-known WAN is the Internet

• MAN

MAN, Metropolitan Area Network connects multiple geographically nearby LANs to one another (usually over an area of up to dozen kilometers) at high speeds. In this sense, MAN connects two remote nodes, making them able to communicate as if they were part of the same local area network. Simply, MAN covers an area larger than LAN but smaller than that of WAN e.g. city. Best example of MAN is the cable television network available in many cities.

• SAN

 SAN stands for Storage Area Network, System Area Network, Server Area Network or Small Area Network. Storage Area Network connects servers to data storage devices through a technology like Fibre Channel

• VPN

Virtual Private Network, is a network that is constructed by using public wires - usually the internet - to connect to a private network (such a s a company's internal network).

Intranet vs Extranet

Intranet

An intranet is a set of Internet services (for example a web server) inside a local network, i.e. only accessible from workstations of a local network, or rather a set of well-defined networks that are invisible (or inaccessible) from the outside. It involves the use of Internet client-server standards (using TCP/IP) protocols such as, for example, the use of Web browsers (HTTP protocol-based client) and Web servers (HTTP protocol), to create an information system inside of an organization or enterprise.

Extranet

An extranet is an extension of the information system of the company to its partners located outside of the network.

Access to the extranet must be secured to the extent that the same provides access to the information system for persons located outside of the enterprise.

Bandwidth

When referring to a data connection, bandwidth or communication speed is the total maximum transfer rate of a network cable or device.

Networking Models

Network model defines a set of network layers and how they interect. There are several different network models mainly:

OSI vs TCP/IP

• TCP/IP

This model is sometimes called the DOD model since it was designed for the department of defense It is also called the internet model because TCP/IP is the protocol used on the internet.

• OSI

The International Standards Organization (ISO) has defined a standard called the Open Systems Interconnection (OSI) reference model. This is a seven layer architecture listed in the next section.

Reference:

• http://ccm.net/contents/266-types-of-networks#lan
• http://www.enggpedia.com/computer-engineering-encyclopedia/dictionary/computer-networks/1620-network-types-types-of-networks-examples-a-definitions
• http://www.webopedia.com/TERM/V/VPN.html
• http://ccm.net/contents/219-intranet-and-extranet
• http://www.computerhope.com/jargon/b/bandwidt.htm
• http://www.comptechdoc.org/independent/networking/protocol/protmodels.html