Computer Networking Flashcards
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What is a computer network?
A computer network is a collection of devices that are connected with each other through a transmission medium where they can communicate with one another by sending and receiving data.
The role of a computer network is to enable the data communication process to take place.
What is data communication?
Data communication is the process where two or more devices in the network exchange information with one another. The communication of devices is a key enabler of the internet.
What are the types of network architectures?
- Personal Area Network
- Local Area Network
- Wide Area Network
- Metropolitan Area Network
What is a personal area network?
A personal area network is also known as a workgroup, or a peer-to-peer network.
A peer-to-peer network is created when two or more PCs are connected and share resources without going through a separate server.
The PAN only serves one individual. It provides data transmission among devices such as computers, smartphones etc.
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What is a Local Area network?
A local area network is a network that connects a small number of nodes in a small geographical area.
LANs can transmit data very fast, but only over a short distance.
The ethernet is the most popular physical LAN layer technology in use today.
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What is a Wide Area Network?
It is a network that connects a large number of devices over a large-scale geographical area. The network uses long-range data links to connect different smaller networks.
WANs can be connected together using the internet, leased lines or satellite links.
What is a metropolitan area network?
It is a network that connects users with computer resources in a geographic area or region larger than that covered by a LAN, but smaller than that of an area covered by a WAN.
It is extremely efficient and provides fast communication via high-speed carriers.
What is a server host?
Provides high-volume storage capacity, heavy data crunching and / or high resolution graphics and can also provide services such as file storage, printer sharing and internet access.
What is a client server?
It provides the user-interaction interface and some or all of the application processing and establishes a connection to the server over a LAN or WAN, such as the internet.
What are some applications of a client-server network?
- File server (FTP)
- Web server
- Mail server (SMTP)
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What are some advantages of a client-server network?
- Security is better since all files are stored in a central location and access rights are managed by the server
- Backups are done centrally so if there is breakdown and some data is lost, recovery procedures will enable it to be restored
- Data and other resources can be shared
- It is easy to replace, upgrade or relocate as they are all independent and request data only from the server
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What are some disadvantages of the client-server network?
- It is expensive to install and manage
- If all the clients simultaneously request data from the server, it may get overloaded. This may lead to congestion in the network
- If the server fails for any reason, then none of the requests of the clients can be fulfilled. This leads to failure of the network.
What is data processing in the client-server architecture?
In the client-server model, data might be processed by either side. A client will send a request message to a server which should respond with the data requested or a suitable message otherwise.
Describe the process of client-side processing.
Data is processed on the client computer, rather than on the server.
E.g. Validation of data entry can be done at the client’s side before the data is sent to the server.
Processing data on the client-side can improve security as it can avoid unnecessary data transfer. It can also adjust styles for different platforms and screens.
Describe the process of server-side processing.
Servers process an enormous amount of data, and can process this data much faster than a client computer.
E.g. Checking user credentials, looking up valid airport locations etc
What is a peer-to-peer network?
It is created when two or more PCs are connected and share resources without going through a separate server.
They do not have a central server controlling the network. Each computer is called a peer, and all peers are connected to one another. It is not suitable for a large network.
What are the advantages of a peer-to-peer network?
- Setup of the network is relatively straightforward compared to others
- Cheaper in terms of implementation, maintenance and cost of hardware needed
- Does not depend on a main server
What are the disadvantages of a peer-to-peer network?
- Data communication can only fully be operational as long as the clients providing the server continue running
- Not as secure as the client-server network model
- Backups and software installations / updates must be performed individually by each device
What is a wireless network?
A wireless network allows for clients to communicate within a network without being physically connected.
What are the advantages of a wireless network?
- Flexibility in mobility and collaboration
- Accessibility
- Scalability
What are the disadvantages of a wireless network?
- Security
- Interference
- Transmission speed
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What is a Media Access Control (MAC) address?
It is a hardware identification number that uniquely identifies each device on a network.
A MAC address is manufactured into every network interface card (NIC) and therefore cannot be changed.
Each NIC has a unique 6-byte MAC address expressed as six sets of 2 hexadecimal numbers.
What is a Network Interface Card (NIC)?
It is a physical device that is used to connect to network devices.
A network device needs to have a NIC installed so that it can be connected to a network wired, or wirelessly.
Why do we need a MAC address when we already have an IP address?
Layer 2 of the TCP/IP communication (LAN setting) uses a MAC address for local communication.
Layer 3 of the TCP/IP communication (WAN setting) uses an IP address for global communication.
What are the network devices needed?
- Hub
- Switch
- Bridge
- Router
- Gateway
- Repeater
- Modem
