Test your knowledge (2)

Network Communication Standards.

1) Why do Manufacturers build products based on the network standards?

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.

2) List four functions included in a network protocol

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  The Type of error checking used


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  The data compression method


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  How the sending device will indicate that it has finished sending a message


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  How the receiving device will indicate that it has received a message

3) Identify the four components of all ethernet frames.

4) Describe how data flows over an ethernet network from the source to the intended destination.

Ethernet communication is performed through 'frames', which contains packets of information. The frames are individually sent by the sending device and receipted back to the sender from the receiver

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

A collision occurs when two or more computers send information into the network at the same time mistakingly, in which time the computers cease further transmissions, and waits a random amount of time.

6)Describe how a token is used in a token ring network

A token is a special signal that continuously travels around the network. If a device wishes to transmit a message over the network, it must attach itself to the token, and is carried to it's destination.

7) TCP/IP uses smaller packets than other protocols. Why is this an advantage on the internet?

The smaller packets can travel can travel down many different paths, and enable load balancing.

8) What standard does a Wi-Fi network use?

Wi-Fi uses the 802.11b or 802.11g standards.

Network hardware and software.

1) List a number of tasks undertaken by a network operating system.

Network operating systems control traffic on the network, and defines how devices communicate with each other. They control file access, managing print queues, keeping track of users their their userIDs and passwords,  authenticating access to network servers and maintaing a log of network usage.

2) What is the role of  a network interface card?

Network interface cards are used to link a computer or resource to a network.

3) Describe the process of roaming on a Wi-Fi network.

Because if the user moves out of the range of the initial AP, they can still access the network.

4) Why would a cafe establish a hot spot on their premises?

For the benefit of the customers. The hot spots allow the customers with portable computers are able to connect to the network without any regard for the particular network they are connected to.

5) Why would networks use switches rather than ordinary hubs?

Switches perform the same task, but do the task much faster, and more efficiently, due to them not sending anywhere near as much traffic as a hub.

6) What are Routers used for?

Routers allow several remote LANs to connect over a WAN, or to join LANs together into a bigger LAN.

7) How does a modem enable a computer to communicate with a network over a standards telephone line?

A modem modulates the digital data it receives from a computer into an analog signal that is compatible with a telephone line, and converts analog signals into digital data that can be transmitted to the revceiving computer.

8) How does a DSL modem differ from a dial-up modem?

Dial-up modems convert the Digital Signals into analog signals, this is not necessary with DSL modems, because they can already respond to digital signals.

Transmission Media

1) Why do new networks use CAT 5 standard cable rather than CAT 3?

Because CAT 5 cabling can carry much larger amounts of data much further, making it much faster.

2) What are some of the disadvantages of using a CAT 5 cable? Why is CAT 5 cable used in so many installations?

3) Why is Fibre-optic cable often used to connect major hubs inside buildings as well as between buildings?

Because it allows many users to use a single strand of the cabling at the same time, and use of it's hightened speed over other forms of cabling.

4) What advantages does wireless networking have over a network that only uses physical transmission media?

It can be installed anywhere, including places where it is difficult to install physical transmission methods, or when it is just easier than having many cables tethered to a single spot.

5) What limitations applies to microwave transmissions?

It requires line-of-sight transmission, so if anything obscures the connection between the sending dish and the receiving dish, the transmission will not be received by the other end.

6) Why is radio wireless networking preferable to infra-red wireless networking?

Because it can be transmitted over longer distances, and is much more flexible because it allows greater portability. Infra-red can only be used effectively over short distances up to five meters.

Test your Knowledge.

Types of Information Systems

1. Explain the main characteristics of the following types of information systems;  

a) Transaction Processing System; Processes data generated by the day-to-day transactions of an organisation.

b) Office Automation Systems; Performs Routine office tasks, such as printing documents, tracking schedules, making calculations and communicating with other departments and clients.

c)Management Information Systems; A computer network that generates timely and accurate information for managing an organisation.

d) Decision Support Systems; Allows users to manipulate data directly, to incorporate data from external sources, and to create data models of "What if" scenarios.

e)Expert Systems;  Designed to analyse data and produce a recommendation or decision.

2. Explain how "What if" questions can be used to determine the best product price when a number of variables affect the price, such as profit per item, number of items sold and the cost of making the item.

A 'what if" questions can be used to create scenarios of the question. For example; it could attempt to predict the outcome of using a certain cost for a certain amount of items, and attempt to predict the outcome of this scenario. The users can then decide if that is their desired result, and if not, attempt another scenario until they create their desired outcome.

3. How is a knowledge base established?

A knowledge base is a set series of facts and rules about the particular type of organisation. These facts and rules are collected and stored on a server on the organisations network.

Networks

1. Define the term 'Network'

A Network connects computers together so they can share data, information and resources, it also allows computers to communicate with other devices.

2. What does groupware on a network allow people to do?

Groupware allows people to work together on the same project at the same time, in real time, allowing all members of the group to see changes made by others and respond.

3. What are the four main advantages in using a network?

• Resouce sharing.
• Allows all computers to access a single internet connection.
• Sharing of software.
• Use of Groupware.

4. What compelling reason would an organisation use to justify resource sharing?

To save money.  All computers cannot be individually connected to printers, scanners and internet connections, so a network allows all computers to access a few resources, saving money.

5. Other than printing, what other resources can be shared on a network?

Internet connections, scanners etc.

6. Describe the benefit to an organisation in providing a remote ordering service for customers over the internet?

Can reduce costs for an organisation, and increase the accuracy of their data processing.

7. How does File sharing on a network avoid problems associated with Data Duplication?

It prevents the file from being duplicated, if one person has updated the document, all users should be using the right edition of the document, rather than having to update everyone's document individually.

Types of Networks.

1. What are the key differences between WANs and LANs?

• A WAN is a network where communications are carried by a medium owned by someone else who is not a part of the Organisation whose data is being transmitted.
  
• A LAN is a network that connects computers and devices within close geographical proximity, such as the same building or home.

2. Why are network points called nodes rather than being called Computers?

Because each point on the network may not necessarily be a Computer, a printer or scanner is also considered a node.

3. Explain the difference between a client and a server on a network.

• A Client is a machine that requests data or files.
• A Server shares or sends the data and files to those clients on the network who ask for them.

4. Describe the rolls of the following on a network.

a) Database Server; Hold databases and allow them to be used by many users.

b)Domain name server; Translate domain names into IP addresses.

c) Proxy Server; Which keep a copy of all recently accessed webpages and files so that if a page is requested again it is delivered from the proxy.

d) Primary domain controller; Accept usernames and authenticate users against their passwords and so allow or disallow access to other resources on a network.

5. On a small network, would a Peer-to-peer network be worthwhile?

Yes, because it's only a small network with few users, so the recourse that needs to be access would only be located in a few places with another user working on it.

6. Napster was a good example of a Peer-to-peer network. It was slower than webservers that use a client/server model. What are the Problems with Peer-to-peer networks?

Over the internet specifically, Peer-to-peer networks are an easy way to get malicious software past the computer security, and infect the computer, causing problems with the computer. These networks can also be slower than a regular network, and far less productive to an organisation.

7. What is a hub?

A hub is a device that takes any incoming signal and and rebroadcasts it down connected wires.

8. Explain why many larger organisations prefer a Star Topology over ring and Bus topologies.

Because it allows all devices to be added or removed from the network with ease, and any cabling can be added to the network at any time. Also problemed devices can be removed without any difficulties.

9. What advantages does a Tree Network Offer?

It combines the advantages from both the 'Bus' and 'Star' networks.

10. What is an Intranet?

An Intranet is a internal, secured environment that has a similar look and feel to the internet, but operates as a local area network.