Outline any 2 Examples of wireless transmission media (2marks)
An organisation that supplies audiobooks over the internet is moving into a new office building.
(a) One reason for networking devices is to provide access to the internet.
(i) Give two other reasons for connecting devices to networks.
(ii) The organisation has chosen wireless connectivity over wired connectivity for its new office building. There is no significant difference in the cost of installing either.
Give three reasons why the organisation might prefer wireless connectivity.
May not have space for cables to be installed
Employees and visitors can move around the building without disconnecting
Adding new users just means giving out the SSID and password
(b) Routers have an important role in how the internet functions.
Describe how a router directs data on the internet.
A large comprehensive school has over 500 computers connected to their Local Area Network (LAN) with a connection to the Internet. (a) Describe, in detail, four disadvantages for the school of having a network of computers compared to stand alone computers
A network manager may need to be employed which might be expensive
Could be infected with a virus that could spread to all other computers
Security problems receive traffic from other networks
Hackers may gain access as the network only as secure as weakest point of entry to data and steal/destroy
The server/switch could go down (main cable break) so all workstations on the network are affected
Can be expensive to set up as Initial cost of servers, communication devices, switches, network software etc.
Substantial Initial disruption: drilling holes, fitting trunking, running cables between buildings etc…
Can have a slow response time due to heavy network traffic so users cannot work as effectively
Detecting network problems can be more difficult on a network i.e difficult to isolate
Can be slow to log in to a network As it slow to download software/check password
Only limited storage space available on network while one has access to all hard disc drive on standalone computer
Time and effort to set up users o Can just start a standalone and use computer
Distinguish between microwave and a radiowave transmission and a microwave transmission (KCSE 2017 PP1)
Microwaves can cover shorter distances. On the contrary, radio waves can travel a long distance. Radio wave is usually propagated through sky mode while microwave uses the line of sight propagation.
State examples of wireless transmission media
State three functions of a network operating system
Below is a labelled diagram of a star topology network.
(a) Other than the items labelled above state the hardware required by every computer to connect to a network
b) Describe how a packet is transmitted from computer A to computer D, including the role of the switch
(a)
(b)
State the function of a switch in a computer network
State five functions of network operating system
State which layer of the TCP/IP model each of the network protocols operates at
HTTP- Application layer
UDP - Transport layer
IP - Internet layer/Network Layer
IMAP - Application layer
HTTP- Application layer
UDP - Transport layer
IP - Internet layer/Network Layer
IMAP - Application layer
State email protocols
Many organisations provide free public access to a wireless network.
Explain three ethical, legal or data privacy issues that an organisation should be aware of when allowing this access
Ochieng manages a network for an organisation.
(a) Two computers are assigned the same IP address.
Explain why Ochieng must change the IP address of one of the computers.
(b) Identify the network topology that requires a server.
Ochieng manages a network for an organisation.
(a) Two computers are assigned the same IP address.
Explain why Ochieng must change the IP address of one of the computers.
(b) Identify the network topology that requires a server.
Differentiate between logical and physical network topology
Physical topology - the physical arrangement of nodes of a computer network
Examples
Logical topology- the way data flows in a network
Examples
Give a reason why microwaves are commonly used for point-to-point communication
State the difference between radio waves and microwave transmission
State the characteristics of each of the following network topologies (KCSE COMPUTER STUDIES 2021 )
i) Mesh Topology (2mks)
(ii) Ring Topology (2mks)
State the characteristics of each of the following network topologies (KCSE COMPUTER STUDIES 2021 )
i) Mesh Topology (2mks)
(ii) Ring Topology (2mks)
Differentiate between Physical and logical topologies
Your friend wishes to install a wireless network in his office. Explain to him the difference between guided and unguided media
Differentiate between bus topology and star topology of networks. What are the advantages and disadvantages of star topology over bus topology
Advantages of Star topology over Bus topology
Disadvantages of Star topology over Bus topology
1 (a) Computer networks are valuable to many businesses and individuals.
(i) State the purpose of network protocols
Any one of:
• To allow connected machines to communicate
• To provide the rules of communication between two networked devices
A school intends to install a computer network. Explain three challenges that the school may experience after the installation (KCSE 2021 Computer Studies Q19(b))
Network Failure - when the network becomes faulty or the network is down, users may not access network resources hence operations of an organization may be brought to a standstill
Security Issues: A computer network can be accessed thus there is an increased chance of hacking
The rapid spread of viruses: Viruses can easily spread to terminals of a computer network which may be very expensive to clear
Cultural and moral effects: adult content may be shared in a networked environment which may be of negative impact on teenagers
Xpat ICT has been tasked to construct a network for an organisation. Explain three factors that the company should consider when selecting the medium for the connectivity (KCSE 2021 Computer Studies Q19c)
Distinguish between a PAN and a LAN
A PAN exist around a single person whereas a LAN covers a larger area
Give an example of where a PAN could be used
Distinguish between a client-server and a peer-to-peer network
Fibre optic cable is available in either single-mode or multi-mode. Outline the characteristics of each mode.
Students are using their wireless notebooks to complete their work in a classroom. They will need to connect wirelessly to a printer to print their answers at the end of the lesson.
Describe how CSMA/CA (Carrier-sense multiple access with collision avoidance) operates in the above scenario.
802.3 is the standard for ethernet wired networks and 802.11x is the standard for ethernet
wireless networks.
Outline why standards such as these are important in the development of network devices and
software.
Describe why fibre optic cable would be used for the backbone of the network. (2 marks)
Describe how the firewalls can ensure the security of the EmergWA network.
Describe a transmission media that would work better in remote areas
The volunteers assisting in an emergency all wear personal protection equipment (PPE) that has an RFID tag sewn into the collar so that they can be tracked if they become lost in a remote location. Identify what RFID is and outline how it works. (3 marks)
Describe two differences between a switch and a repeater
Describe the role of a repeater when used in a network.
a repeater will amplify a signal and resend it to overcome reduction in signal strength (attenuation) because over a distance network signals diminish in size/amplitude (are attenuated) due to characteristics of the media.
Satellite services are used to provide broadband internet connectivity to regional and remote areas of Kenya. State one advantage and one disadvantage of using satellites for this purpose.
Advantages
Disadvantages
State the primary function of the Dynamic Host Configuration Protocol (DHCP) protocol.
List three characteristics of Internet Protocol version 6 (IP6).
Explain two ways in which an interpreter and a compiler are different.
Explain each of the strategies listed below.
(a) Phishing
(b) DoS
(a) Phishing
(b) DoS
List two primary functions of a domain name server.
When developing a network security policy, it is important to understand the threats that can be made against a network. ‘IP spoofing’ and ‘back doors’ are two techniques that can compromise the security of a network. Describe each of these techniques.
IP spoofing
A technique used to gain unauthorised access to a computer whereby an intruder sends messages to that computer from a false IP address
Back door:
An undocumented method of gaining access to a program, online service or an entire computer system
Explain, with examples where appropriate, the following five computer terms.
(a) Buffer
(b)batch processing
(c) e-commerce
(d) simulation
(a) Buffer
(b)batch processing
(c) e-commerce
(d) simulation
(e) Email
Describe three possible threats to the computers connected to the network and give one way each threat can be reduced or prevented
Virus / trojan / worm / malware
Prevention
Spyware / malware / keylogger
Prevention
Data interception / passive
Prevention
Phishing
Prevention
Pharming
Prevention
Hacker
Prevention
1. State two ways in which a computer may be used in a healthcare sector other than record keeping
Describe what is meant by a MAC address.
Give two other uses of hexadecimal in computer science.
A company has a website that is stored on a web server.
(a) The website data is broken down into packets to be transmitted to a user.
Describe the structure of a data packet.
A web server has an internet protocol (IP) address. Give three characteristics of an IP address.
Identify the network component that uses the IP address to send data only to its correct destination
Router
The website has a uniform resource locator (URL).
An example of a URL is given.
https://www.google.co.ke/index.html
Complete the table to identify the name of each section of the URL.
https : protocol
google.co.ke: domain name
/index.html: webpage/file name
State two advantages and one disadvantage of having a network of computers, rather than a series of stand-alone machines, in a school classroom.
Advantages
Disadvantages
Explain the difference between
(i) serial and parallel,
(ii) simplex and duplex
modes of data transmission.
When data is transmitted it is subject to corruption. Explain how a parity check could be used to determine whether corruption has taken place.
Explain, using examples where appropriate, the meaning of these computer terms
(a) byte ..................................................................................................................................
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......................................................................................................................................[2mks]
(b) compiler ............................................................................................................................
..........................................................................................................................................
......................................................................................................................................[2mks]
(c) handshaking .....................................................................................................................
..........................................................................................................................................
......................................................................................................................................[2mks]
(d) technical documentation ..................................................................................................
..........................................................................................................................................
......................................................................................................................................[2mks]
(e) simulation .........................................................................................................................
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......................................................................................................................................[2
(a) byte
(b) compiler program
(c) handshaking
(d) technical documentation
(e) simulation
Give one example of wireless technology
method of transmission e.g
device e.g.
Give one benefit and one disadvantage of the use of wireless technology.
Advantages
disadvantages e.g.
Give one advantage using a star network rather than a ring network.
Explain what is meant by the two terms download speed and upload speed
download speed :
– speed at which information/data is transferred FROM server/Internet
– speed at which information/data is transferred TO the user’s computer
upload speed :
– speed at which information/data is transferred FROM user’s computer
– speed at which information/data is transferred TO the Internet/server
Give two advantages of using broadband rather than dial-up
Give two different scenarios when a fast broadband connection is essential.
– when transferring large files/attachments with emails
– when streaming music/video files/bit streaming
– when using VoIP/video conferencing
– software updates
– online transactions
– Using VLE (Virtual Learning Environment)
Give one advantage of a star network when compared to a ring network.
– if one station/cable fails, others are not affected
– easier to identify faults when using star topologies
– it is easier to expand this type of network
– performance doesn’t deteriorate under load
Describe how a FRID works.
RFID stands for radio frequency identification. There is an RFID reader and tag.RFID is used in contactless credit and debit cards as well as in some hotel room cards. Inside an RFID tag is a chip that contains a small amount of memory. The chip is attached to a coil of wire which acts as an antenna. When an RFID tag is scanned, the reader emits radio waves which are picked up by the tag’s antenna. The power induced in the tag’s antenna from these waves is enough to power the chip which then uses its antenna to emit its own radio wave, which contains the information held on the chip. This wave is picked up by the reader which decodes the information and returns the information to a computer.
Website data is broken down into packets to be transmitted to a user. Describe the structure of a data packet.
It has a header
It has a payload
It has a trailer.
Give three characteristics of an IP address.
A workshop has a lot of heavy machinery operating throughout the day and requires a cable to connect a workstation to a switch. Which of the following, unshielded twisted pair (UTP) or shielded twisted pair (STP) cable, would be the more suitable? Justify your response.
Shielded twisted pair cable:
A twisted pair cable is made up of four pairs of twisted copper wires, a shielded twisted pair cable applies a shield to each one of the pairs on a cable or to all of the pairs together. This shield can reduce EMI (electromagnetic interference), which would be emitted from heavy machinery. This increased data transmission quality in the workshop. STP can also reduce crosstalk.
Outline a factor that can influence the performance of a network.