INTRANETS

MR ROSSUNIT 3

IT APPLICATIONS

DEFINITION

• An intranet is an internal, secured environment that has a similar look and feel to the Internet, but operates as a local area network.

• An intranet provides easy and fast access to information by employees in a familiar environment while keeping the information secure from the general public.

BENEFITS OF INTRANETS

• These include -– access to information in a controlled manner – communication within the organisation– messages that log hardware and software problems with

technical support personnel– contacts of who to approach for various problems or issues– training through the publication of online user guides and

computer-based training programs.

• WHAT INFORMATION, DOCUMENTS AND RESOURCES ARE ON THE SCHOOL INTRANET?

NETWORK COMMUNICATION STANDARDS

• These have protocols that are an agreed sets of rules and procedures for computers to exchange information.

• These protocols are like humans agreeing to speak the same language during a conversation.

• For two computers to exchange data, they must be using the same protocols.

• Network standards have been established to overcome the problems of incompatibility on a network and to ensure that hardware and software components can be integrated into any network.

• CAN WE COME UP WITH DIFFERENT HUMAN PROTOCOLS THAT WE USE EVERY DAY

PROTOCOL

The protocol determines:• the type of error checking used• the data compression method, if one is used• how the sending device will indicate that it

has finished sending a message• how the receiving device will indicate that it

has received a message.

WHAT IS ETHERNET?• Ethernet is a network standard

that describes communication over a single cable shared by all devices on the network.

• Any devices connected to this single cable can communicate with each other. This gives the ability for the network to expand if more devices needed to be added.

• Ethernet communicates between nodes in short messages called frames.

• Frames also contain parity information, to check if the frame has arrived correctly.

NETWORK PROTOCOLS

There is a standard protocol for each network communication task, such as:

• how to send data over the Internet (TCP/IP)

• how to send and receive email (POP, IMAP)

• how to request and deliver web pages (HTTP)

• how to request and deliver files (FTP)

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• This protocol is the most common method of putting data together for sending and receiving over networks.

• This is the universal protocol for internet communications. It is defined as how data is moved from one part of a network to another.

• Made up of 2 complementary protocols…

• TCP (Transport Control Protocol)

• And IP (Internet Protocol)

TCP / IP

• TCP (Transport Communication Protocol)

• Breaks files into packets to be sent across the internet or a network. Each packet contains:

- the address of the sender

- the destination address

- a chunk of data (e.g. 1K)

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Protocols – TCP

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• IP (Internet Protocol)…

• Once a file has been chopped into packets, the IP delivers each packet to its destination.

• each packet can take a different route from A to B, bouncing from router to router getting more precise with each hop.

• the route is dynamically chosen for each packet, based on internet conditions at that time.

Protocols – TCP/IP

802.11 Wireless Standard(WI-FI)

• The 802.11 standard defines how two computers or devices can communicate using radio waves.

• A network that uses this known as a WI-FI network. Wi-Fi is known as wireless fidelity.

• Wi-Fi Networks allow computers up to 50 metres apart to connect without the need for wires.

802.11 Wireless Standard(WI-FI)

• Computers fitted with a Wi-Fi network card can split the available radio bandwidth which allows a number of computers using these cards to talk at the same time with interfering each other.

• The 802.11 standard uses techniques that are similar to the Ethernet standard to control data flow. For this reason, a Wi-Fi network can be easily connected to a wired Ethernet network.

Network communication standardsQuestions 22, 24, 26, 27

22.Why do manufacturers build products based on network standards?

24. Identify the four components of all ethernet frames.

26. How does a collision occur on a network? How does ethernet avoid repeated collisions of the same transmissions?

27. TCP/IP uses smaller packets than other protocols. Why is this an advantage on the Internet?