NETWORK HARDWARE AND SOFTWARE MR ROSS UNIT 3 IT APPLICATIONS

NETWORK OPERATING SYSTEMS A Network also requires a number of hardware and software components to allow computers (and other devices) to communicate with each other The network operating system is software that controls traffic on the network and defines how devices will communicate with each other. A NOS has two components usually – a server software and a client software

SERVER SOFTWARE Network server software is installed on the network servers It performs tasks such as controlling file access, managing print queues, keeping track of users through their User IDs and passwords. It also allows authenticating access to network servers and maintaining a log of network usage and problems

CLIENT SOFTWARE This type of software is installed on each computer and establishes a connection on the network through a Network Interface Card (NIC). Each computer will then use the network operating system to create their own packets of data and transmit at appropriate times to ensure successful communication There are 3 major providers of NOS – Windows, Novell and Apple. It is preferable for all machines on the same network to be using the same network operating system, as it makes network maintenance simpler. It also ensures that, as there is only one set of instructions for the users, they can help each other where possible.

WEB CLIENT SOFTWARE Web client software includes web browsers, electronic mail, videoconferencing and instant messaging. A web browser allows a user to view pages on the internet and manages the links used to jump from one document to the next. Common web browsers are Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Apple Safari and Opera.

WEB CLIENT SOFTWARE Electronic Mail applications operate over a network such as the internet or intranet. Simple text messages can be sent over a network supports the ability to attach files A network will usually have a mail server that is used to manage the flow of .

WEB CLIENT SOFTWARE Videoconferencing allows users to send audio and video signals over the Internet. It is used to bring people together electronically for a meeting. A video camera, microphone and speakers must be connected to users’ computers. A chat room involves users of the Internet engaging in real- time typed ‘conversations’.

SOFTWARE FOR WEBSITES URL = Uniform Resource Location. The user will type this into their browser and this browser uses the URL to request the required page from the host server. The URL sent includes: - – The protocol used for communication – Name of the host server – Name of the page requested. The first part of the URL is the protocol (http), followed by the name of the host server, and then the name of the file. HTTP = Hyper Text Transfer Protocol. This is a standard used for sending and receiving information on the internet. The http protocol is used to access pages written in hypertext markup language (html).

9 Domain name servers (DNS) – a distributed database on thousands of computers across the world - convert URLs into IP addresses. Like a phone book – look up a name (URL) to get a number (IP address). ADDRESSING

WEB SERVER SOFTWARE This type of software usually provides the content using the http protocol. This is in the form of html documents, images and other resources Popular examples include Apache and IIS. To transfer a page to a client’s browser, the web server needs to know the client’s IP address. This means that the client is not anonymous to the web server. Proxy Servers are used to sit between the client and the rest of the internet. This acts as a form of increase privacy for the user as it blocks sending its identity. Another use is to speed up traffic on a network. They can also be configured to block certain websites.

DIFFERENT WEBSITE SERVERS Simple Mail Transfer Protocol (SMTP) – is used on servers to handle the sending and receiving of client s. When an is sent, the SMTP server is given the address of the sender, address of the recipient and the text. Post Office Protocol (POP) – this server is used to store messages. File Transfer Protocol (FTP) – software allows the uploading and downloading of files between computers on the Internet. Cross Platform applications software used in creating websites are Flash and Java.

12 The Network interface card (NIC) allows a stand-alone computer to connect to a network. Is connected to a network by wires, radio waves, infra- red, microwave or fibre optic. Can be cabled or wireless Usually built into motherboards. Separate card not needed in most cases. NETWORK INTERFACE CARD

Many important devices can connect directly through a NIC. These include a printer, computer, server, photocopier, fax and routers. For a NIC to work at its maximum speed, all the other network devices between it and the server must have at least the same bandwidth (data-carrying capacity). WHY WOULD A NIC BE CALLED A NODE? 13

WIRELESS ACCESS POINT (AP) This is used to connect wireless communications devices to a wire or wireless network. It is used to relay data between devices on each side of an AP. The process of being able to move around a network is called roaming. A benefit of an AP is the as the user you have mobility with full access to the network A Hot Spot is a location where a user can communicate with an AP.

GROUP WORK Read the Issue regarding “Swindon promises city-wide Wi-Fi” Complete questions 1 and 2