NETWORKING BIT103

Learn to plan, facilitate installation and manage computer networks

A computer network, commonly just called a network, is a system of interconnected computers (and devices) that operate interactively. Any number of computers may be connected into a network, from two to dozens, hundreds, thousands or even millions. Networks typically include other devices such as printers, external hard drives, modems and routers, etc. The network provides communications between the devices so that they may share data, software, hardware and resources.

PHYSICAL TOPOLOGIES

Star

The computers in a star topology network are connected to a centralised hub or switch, and communications between the computers flows through the hub or switch. Different types of cables can be used in this topology, for example, coaxial, fibre optic or twisted pair cables.

Bus

The client computers in a bus network are connected by a shared line, called a bus. This conceptual architecture is also used on motherboards of computers, and in some versions of Ethernet networks.

Mesh

A fully or completely connected network is a mesh topology. In this type of configuration, every workstation or device on the network is connected to all others in the network. Mesh topologies are very expensive to implement, as there are large overhead costs with an excessive need for cabling. Also, these networks are difficult to maintain and expand.

Study Computer Networking for Networking Computers

Learn to plan, facilitate installation and manage computer networks.

COURSE STRUCTURE AND CONTENTS

There are ten lessons in this module:

Networking Terms, Concepts and Standards
Network Topology, Architecture and Transmission Media
Network Components and Hardware
Network Design and Planning
Network Upgrading and Project Management
Network Protection and Maintenance
Understanding Network Connecting Options
Installation and Configuration of Network
Basic TCP/IP Services and Applications
Troubleshooting Tools for TCP/IP Networks

Duration: 100 hours

Extract from Notes

Types of Computer Networks

There are many types of computer networks, often defined by the types of users, the purpose of the network, or most commonly, the size and configuration of the network connections and devices attached to it.

Through the years of network development, various names for networks have been used and which describe some feature of the network. The most common network names, which are still in use today, are:

LAN – Local Area Network
WAN – Wide Area Network
WLAN – Wireless Local Area Network

LAN (Local Area Network)

A LAN is a network of computers and devices connected over relatively short distances, for example within a room, a home, a small office or building, a school or other small business or organisation. Sometimes a single building may contain a few small LANs (perhaps one per room or work group), or a group of nearby buildings may be connected to form a LAN. In the TCP/IP network protocol, a LAN is often, but not always, implemented as a single IP subnet. (The TCP/IP protocol is explored in later Lessons.)

In addition to operating in a limited space, LANs are also typically owned, controlled and managed by a single business or organisation. They often use certain connectivity technologies, typically Ethernet and Token Ring (network technologies which are discussed in later Lessons).

WAN (Wide Area Network)

As the name suggests, a WAN covers a large physical area, and is usually collection of interconnected LANs. The Internet is the largest WAN and which spans the entire planet.

Connections within a WAN may be coaxial or fibre optic cabling, ISDN lines, radio waves or satellite links. Server software is needed for operating a large network. The server software controls the data communications within the network, and manages access to the individual devices and services offered on the network.

Network routers connect LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address. A WAN differs from a LAN in several important aspects. Most WANs, like the Internet, are not owned by any one business or organisation, but rather are a collective of interested parties, with distributed ownership and management. WANs tent to use technologies like ATM, Frame Relay and X.25 for connectivity over the longer distances (discussed later in this course).

Home Networking and WLANs (Wireless Local Area Networks)

A WLAN is a LAN based on Wi-Fi, a wireless network technology. Residences typically use a single LAN and connect to the Internet WAN via an ISP, using a broadband modem. The broadband modem is a device which makes a connection to the ISP over a high speed/high data volume cable connection. The ISP provides a WAN IP address to the modem, and all the computers participating in the home network use LAN (or private) IP addresses.

All the computers on the home LAN can communicate directly with each other, but must have their communications routed through a central gateway, typically a broadband router, to reach the ISP.

The individual computers within the home are increasingly connecting to the Internet (i.e. accessing the broadband modem) via a wireless router. This means that the LAN of the home can be referred to as a WLAN.

Free WLAN Connection

In the 21^st century, many commercial businesses and community centres (e.g. libraries etc.) now offer their customers free limited wireless access, to encourage users who need to work remotely, to do so from their premises while enjoying their meals and beverages. For example, both Starbucks Coffee and McDonald's Restaurants now offer free wireless connections to users, as this is seen as an important value added service in the modern world.