Networks and the effects of using them Flashcards
What is a Network Interface Card (NIC)?
is needed to allow a device to connect to a network. It is integrated in the motherboard. They turn binary data into an electrical signal that allows access to a network. Examples- wireless, wired or USB. Contains the MAC address.
What is the Media Access Control (MAC) address?
is a number which uniquely identifies a device when it is connected to a network. It is made up of 48 bits which are shown in 6 groups of hexadecimal digits with general format of NN-NN-NN (manufactures code)-DD-DD-DD (device serial number). Cannot be changed.
What are data packets?
Data is moved around the network in the form of data packets. Whenever user sends data it is split up into a number of packets and each packet is transmitted separately. The packets of data will usually have a header e.g. The senders IP address which allows the router to determine the packet’s next path.
What is an Internet Protocol (IP) address?
An IP address, or Internet Protocol address, is a series of numbers that identifies any device on a network. Computers use IP addresses to communicate with each other both over the internet as well as on other networks
What are hubs?
are a hardware device that can have a number of other devices connected to them. They are used to connect devices together to form a local area network (LAN), often in the same building. Hubs are not very secure because every device will receive the data package.
What are switches?
are intelligent versions of hubs. Each port on the switch connected to a device will have a matching MAC. Switches send data packets to specific devices only. Used to exchange data within their own LAN.
What is a bridge?
are devices that connect one LAN to another LAN that uses the same protocol. Used to connect together different parts of a LAN so they can function a single LAN. They cannot communicate with other external networks e.g. The internet.
Explain how a router works.
- Data packets are sent from a computer to a switch/hub
- The router checks the IP address and notes the data is not intended for the same network
- The data packets are then forwarded onto the internet
- The IP address matches that of the router; this ensures that each data packet is eventually forwarded to the router
- The router recognises the IP address of each data packet refers to correct network and forwards them to the switch which then directs each data packet to the correct computer
Why do we use routers?
To route data packets from one network to another network, based on IP addresses. It can do this because each rooter has its own IP address. Routers are used to join a LAN to the internet.
Can a router act as a switch? When does it do this?
Modern routers combine the functions of a router and a switch- this means that they store MAC addresses and IP addresses to enable data packets to be sent to the correct network and then to the correct device on the network
What are the differences between a bridge and a router?
- Routers scan a device’s IP address but Bridges can scan a devices MAC address
- The main objective of a router is to connect various networks (types) together but The main objective of a bridge is to connect LANS together
- Both send out data using data packets
- A router Connected networks will use DIFFERENT protocols but a bridge connects networks together that use the SAME protocols
- A routing table is used to direct data packets to the correct device but bridges do not make use of routing tables
- A router has more than two ports but a bridge has only two ports
What is an internet?
A global computer network providing a variety of information and communication facilities, consisting of interconnected networks using standardized communication protocols. In a school environment everyone and anyone can use this network including staff, pupils and the headmaster as it is a public network. The public facing of a network- no username or password required.
What is an intranet?
An intranet is a private network contained within an enterprise that is used to securely share company information and computing resources among employees. In a school environment an intranet is used to build a private, secure network that can only be accessed by the students, staff, headmaster and owners of the school. Or be used to help store and manage important documents.
What is an extranet?
An extranet is a private network similar to an intranet, but typically open to external parties, such as business partners, suppliers, key customers, etc. The main purpose of an extranet is to allow users to exchange data and applications, and share information. In a school environment an extranet may be sued for students and staff to access to shared information from home and connect with pupils and teachers at home. Or for the suppliers of the school
Define the term LAN.
A local area network is when computers or devices are connected together over a small geographical area, such as within a home, a building or one site. A LAN can be created to share data or hardware such as a printer, or to share an internet connection.
Define the term WLAN.
They are similar to LAN’s, but there are no wires or cables. They provide wireless network communications over fairly short distances using radio or infrared signals instead of using cables.
What are the advantages of LANs?
They allow the sharing of resources such as hardware (e.g. Printers and scanners) and software (e.g. Word processors and photo editing software)
They permit easy communication between users of the LAN (e.g. By using simple text messaging between computers on a network)
They use a network administrator that ensures security and use of the LAN is constantly monitored
What is an access point (AS)?
These are sometimes known as Wireless Access Points (WAP)
A wireless access point (wireless AP) is a network device that transmits and receives data over a wireless local area network (WLAN), serving as the interconnection point between the WLAN and a fixed wire network.
What are the important points of wired networking?
Produces a more reliable and stable network
Data transfer rate tends to be faster
They tend to be cheaper than wireless networking
Cabled networks lose the ability for devices to be mobile
Having a lot of wires can lead to tip hazards
What are the important points of wireless networking?
It is easier to expand the networks and it is not necessary to connect the devices using cables
This gives devices increased mobility, as long as they are within range of the APs
No cabling, so there is a safety improvement and increased flexibility
Data is less secure than with wired systems
Data transmission rate is slower for cabled networks
It is possible for signals to be stopped by thick walls
Increased chance of interference from external resource
Define the term WAN
A wide area network is when computers or devices are connected together over a large geographical area
Can a WAN be made up of lots of LANs? How do they do this?
Yes The WAN network can be made up of multiple LAN and MAN networks. A WAN is a network that connects multiple LANs over a long distance to allow devices to communicate over a wide area.
Give 2 more examples of when a WAN might be used.
Communicate using voice and video and accessing data storage and remotely back up data.
Give an example of how banks might use a WAN?
Community banks and credit unions utilize their WAN’s to transmit data to and from their branches and carry out daily functions regardless of location.
What is the largest WAN on the planet?
The internet
How do WANs connect? 2 ways giving examples for each
Ethernet cable or cellular radio signals
What does a typical WAN consist of?
It consists of two or more interconnected local area networks which includes a server and a workstation
What is the transmission frequency used for Bluetooth and Wi-Fi?
Bluetooth: 2.4GHz
Wi-Fi: 2.4, 5.0 GHz. 2.4 has a longer distance (wavelength allows it to pass through barriers). 5.0 has much faster connection
