TASK 1[D1]
Computer Network
A computer network is when two or more computers are connected together to share resources such as hardware, data, and software. There are various types of network services available that Sixes and Sevens firm can apply to their accounting group such as email, file transfer, conferencing e.t.c[D2].
Network Services
The whole point of a network is to allow computers to share resources, such as hard drives and printers and to allow communication. On major networks this requires a "server" and a "client", both together provide the following services:
* E-Mail
* File Transfer
* On Line Databases
* Bulletin Boards
* Conferencing[D3]
E Mail
Electronic mail (email) offers all of the facilities provided by fax and teletex but is paperless.
Electronic mail; offers the additional advantage of being able to store messages even when the destination terminal is busy.
E Mail Features
Terminal to prepare and store messages
A communication link with other workstations within the network
A central controlling computer which will be your email server
A directory of addresses
A central mailbox
A system which dates the messages
A function that notes that a message has been received by the addressee
A facility to multiple-address, so that all members of a particular working group can be sent a message simultaneously
A prioritising system, so that messages can be identified as either important or routine
A storage facility in order to keep, in the memory, those messages that have not yet been received.
Compatibility with existing equipment and computer systems[D4].
E Mail Advantages
Savings on stationery and paper costs.
Savings on telephone costs.
Rapid transmission.
Integration with other systems.
The recordings of all transmissions so that accurate costings can be obtained.
Allowing addressees to peruse their own electronic mail at leisure[D5].
File Transfer
What file transfer basically is is the movement of one or more files from one location to another. It's a facility which enables a user to transfer files electronically to another computer or to a printer.
Transfer across the internet from file transfer protocol (FTP) sites is also common. It's a network protocol used to copy a file from one host to another
Online Database
What an online database is, is a database accessible from a network or the internet. It's mostly accessed through the internet and normally contains a reasonable amount of useful information. Examples of online databases are the following below:
* Internet Search Engines
* Online catalogues
* Support Sites
* Forums
* Online Data Storage[D6]
Bulletin Boards
Bulletin boards operate rather like a notice board,
Allows individuals to leave messages,
Various information, such as notices or memoranda to all staff can be found on an internal bulletin board
A bulletin board may be setup by a service or product provider to keep users or purchasers informed of new developments
Internet, bulletin boards, either free or requiring a subscription, which hold some very useful information which can be accessed and downloaded by any user.
Conferencing
Conferencing is a process whereby communications is available between multiple computer users while all are connected to the Internet, and most likely see the same screen at all times in their Web browsers.
Some Web conferencing systems include features such as texting, VoIP (voice over IP) and full-motion video.
Although In its most primitive form, conferencing allows number of individuals to speak to one another simultaneously over telephone network. Below are some examples of conferencing:
* Video-conferencing
* Chat rooms
* Telephone conferencing[D7]
Types of Networks
Local Area Network (LAN): A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link. The computers are connected in a geographical close network, such as in the same building campus or could span two buildings of a similar office park. Usually, the server has ...
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Although In its most primitive form, conferencing allows number of individuals to speak to one another simultaneously over telephone network. Below are some examples of conferencing:
* Video-conferencing
* Chat rooms
* Telephone conferencing[D7]
Types of Networks
Local Area Network (LAN): A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link. The computers are connected in a geographical close network, such as in the same building campus or could span two buildings of a similar office park. Usually, the server has applications and data storage that are shared in common by multiple computer users. A local area network may serve as few as two or three users for example, in a home network or as many as thousands of users in a school network or college[D8].
Peer to Peer Network: No dedicated servers which makes all computes equal and are known as PEERS. Each computer acts both a server and client and the users perform their own administration.
Client Server: Used in an environment with more than 10 users where a dedicated SERVER is used. Provides centralised control of administration and the sharing and resources.
Metropolitan Area Network (MAN): A MAN is data network designed for a town or city. In terms of geographic breadth, MANs are larger than local-area networks (LANs), but smaller than wide-area networks (WANs). MANs are usually characterized by very high-speed connections using fiber optical cable or other digital media.
Wide Are Network (WAN): WAN is a computer network that spans a relatively large geographical area. A WAN consists of two or more local-area networks LANs. Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites. A WAN also consists of a number of LANs connected over a large geographical area - this could be more than one location in the country - London Sheffield or around the world. The largest WAN in existence is the Internet[D9].
Differences between Network Types
The two basic types of network are the LAN and WAN. LAN stands for local area network and WAN stands for wide area network. There are obvious differences between the two network types. To begin with local area networks. They are smaller networks, usually within an office base. Connections between the workstations are physical, with cables, and all the office resources are shared and distributed between the network workstations. The most common type of LAN is that of Ethernet.
WAN, or wide area networks, are broader geographic networks, like one city to another. They are more of a collection of interconnected LAN networks. Other WANs, provided by service providers, connect local networks to the Internet. In actual fact the Internet is more a specific Internetwork, not a straight WAN.
While LANs are smaller, collectively they can be linked to create the WAN.
MANs on the other hand are a kind of network that's not mostly used but it has its own importance for some government bodies and organizations on larger scale. MAN, metropolitan area network falls in middle of LAN and[D10] WAN, It covers large span of physical area than LAN but smaller than WAN, such as a city.
Network Topology
The term topology or more specifically network topology refers to the physical layout of computers, cables and other components on the network. This is commonly known as the design of network. Referred to as:
* Physical Layout
* Design
* Diagram
* Map
The design or network topology choice can impact the:
* The type of equipment the network needs
* Capabilities of the equipment
* Network growth
* The way it is managed
Standard topologies
* Ring
In this topology, all computers and devices are connected to cable that forms a closed loop. Each computer on this type of topology acts like a repeater and boosts the signal before sending it to the next computer. It transmits data by passing a "token" around the network. Hence this type of network is commonly called a token ring network. Similar to the Bus topology, if one computer fails, the entire network goes down[D11].
* Star
All computers and devices are connected to a centrally located hub or switch. The hub or switch collects and distributes the flow of data within the network. It's better to use a switch than a hub because a switch transmits the data to the intended recipient rather than to all hosts on a network.
* Line/Bus
All computers and devices are connected in series to a single linear cable called a trunk or sometimes called a backbone. Both ends of the trunk must be terminated to stop the signal from bouncing back up the cable. Because the bus topology does not have a central point it is difficult to troubleshoot problems. Also, a break at any point along the bus can cause the entire network to go down[D12].
Protocols
Protocols are rules and procedures for communicating, for communication to be successful computers must agree on protocols.
Purposes and Functions of Protocols
There are different types of protocols and each Protocol has different purpose and function. Networking protocols enable computers to exchange data with each other in a meaningful, organized, and efficient way. Computers rely on protocols to ensure each computer "understands" what the other computer is sending it. Both computers must use the same protocol if they are to exchange information with each other successfully. Most common protocol is TCP/IP used by the Internet and pretty much all operating systems.
The purpose and function of TCP/IP
Transmission control protocol/Internet protocol (TCP/IP): the combination of protocols that enables the Internet to function. TCP deals with the process of sending packets of information from one computer to another. IP is the process of passing each packet between computers until it reaches its intended destination.
Configuration of TCP/IP
* Locate the My Computer icon on your desktop and double-click it with the mouse.
* Double-click the Control Panel icon.
* Double-click the Network icon.
* After clicking on the network icon, right click on your local area network and select properties
* A box like the one below should pop up.
* When seeing this click on the Internet Protocol (TCP/IP) and select properties.
* To specify TCP/IP address settings, do one of the following:
To get IP settings automatically using DHCP, click Obtain an IP address automatically, and then click OK just like the image below.
OR
* To specify an IP address, click Use the following IP address, and then, in the IP address, Subnet mask, and Default gateway boxes, type the IP address settings e.g. your IP address settings could be like the setting below.
IP address: 192.168.1.14
Subnet Mask: 255.255.255.0
Default gateway: 192.168.1.1
TASK2
Network Security
Sixes and Sevens accounting firm can protect their clients' data and improve their security by following the methods below.
Controlling access to a network:
The ultimate aim of any network security attack is to either deprive you of use of your system or more commonly to give at least partial control of your system to the cracker but Sixes and Sevens could prevent this by controlling access rights in their network by issuing rights to each of the staffs working in their company e.g. different files and folders can be only viewed by particular staffs. Another way for them to control access to their network is to issue usernames and passwords to staff that require computers to carry out their daily tasks. It's also advisable to own hard to crack but memorable passwords.
Additionally an attacker could prevent you from using your own system because after gaining access to a network an attacker could do almost anything such as blocking traffic, which results in a loss of access to network resources by authorized users; Flood a computer or the entire network with traffic until a shutdown occurs because of the overload and to prevent problems like this, its important to always update the operating system and install patches for any software on your computer, more importantly get some kind of a hardware firewall connected to your system also handling emails correctly e.g. never open or run an email attachment on the office computer because they normally contain all sorts of viruses. It's also advisable to run system scans to check for problems or vulnerabilities[D13].
Virus protection:
Protecting the integrity i.e. trustworthiness the system and data is vital in a network. Having virus protective software on your system is recommended because once a virus attacks a network it can become a nuisance and damages important files and data. Once it infects a system, it can always transfer itself unto other computers. Antivirus software may be used to detect and remove viruses from a computer, but the software must be updated frequently for protection against new viruses. Even though there's virus protection it better not to open an email attachment unless there's the certainty you were expecting to receive it because There is always a possibility that the attachments might contain new virus that the anti-virus software is not able to detect it at all. Moreover it's best to try and avoid referring, storing or copying files (programs and documents) from unknown or untrusted sources such as downloads from Internet because the site where you store information might not be safe and it could also get attacked so your data could be damaged or infected.
A good antivirus program is "Avast Antivirus" its known for its comprehensive protective ability. Its comes equipped with a silent firewall that blocks even attacks from hijacked websites. Fact even shows over a hundred million have avast protecting their computer system moreover avast has key technologies no other antiviruses have such as its behaviour shield and beautifully engineered antivirus and spyware engine. So for the utmost protection for your firm avast is the solution.
Backup and recovery[D14]:
Backup of sixes and sevens client data is essential if the firm is to be successful. It's important to backup data such as clients' home address and phone number, the account details of all their clients and even the date they joined and left the firm. More data that could be backed up is the staff details e.g. the date they were employed to be part of the sixes and sevens team. Moreover the way they are paid such as if its electronic pay or manual.
For the firm to be successfully immune to data loss they can archive data and to protect against network failure. To prevent computer media fails, one golden rule is to always back up. Backup simply means you are keeping at least one copy of the original data, preferably not in the same disk media. Furthermore an attacker would modify data of sixes and sevens firm clients and damage so that's why it's important to backup data regularly. To lower the chances of media failure, Protect electrical components by using computers in a dry, shaded, dust-free area additionally it's recommended to make sure your hard drive is in a secure environment, away from potential accident areas. Also it's important that you hire trusted and experienced people to handle the data in your firm because most causes of all media fails situations are results of human errors. So it's advisably to never attempt any operation, like installations or repairs when you have no experience. Furthermore it's better not to try and move a computer when it's turned on, Maintaining security on personal files and folders to prevent unauthorized changes.
An example of a backing up and restore software is a programme called "Acronis Backup Software" By using this enhanced backup software, you are not only able to automatically back up everything on your system, but you can also save storage space by managing your backups by using incremental backups. Online backup is available as well so there's no need to ever worry about losing your backups.
Hacking and firewalls[D15]:
A small amount of virus can actually be placed on your computer remotely by hackers. Installing a firewall or using the firewall that's built into your operating system such as windows 7 can help provide a helpful defence against these hackers. Firewalls also help prevent unauthorised because it helps block any unwanted remote access to computer such as people trying to connect to your wireless internet without the right to do so. It is also recommended to keep your firewall up to date as well because if you have an outdated firewall, there are most likely to be hacking techniques developed to bypass it. Another of way your computers could get infected is by visiting the wrong websites e.g. if a website is displayed as a high risk site don't go there because from there your computer could be affected. So it's important not to visit high-risk websites or click on any of the links there.
As accounting firms it will become a hard hit if any of your computers get hacked so another good way to prevent computer hacking is to establish a corporate security policy that details practices to secure the network. This policy will ensure employees choose passwords with letters, numbers and if possible symbols. This sort of policy should prevent network tampering and unauthorized entry. Also during installation, non essential network services should be disabled.
[D1]Where is the original with comments
[D2]Good
[D3]Good
[D4]Good
[D5]Good
[D6]Good research
[D7]Good
[D8]Good explanation with valid diagram
[D9]All good definitions although they are all a little brief
[D10]Not really sure what the differences you are highlighting here
[D11]Good
[D12]Good topologies identified well
[D13]Good
[D14]You have not stated what the data is to be backed up to
[D15]Good
