Networks Flashcards
What is a LAN?
- Local Area Network,
- A network that covers a small geographical area,
- It can be wired or wireless,
- Most homes use LAN.
What is a WAN?
- Wide Are Network,
- A network that covers a very large geographical area,
- Connection is achieved using telecommunication companies such BT or Sky,
- Is often used for joining companies.
What is a PAN?
- Personal Area Network,
- Has a very short range (10m), normally centred around a single person,
- PANs often uses common wireless technology (Bluetooth), to connect devices,
- Don’t require any additional hardware,
- An example, would a hotspot.
What are the benefits of having a network?
- Sharing files,
- You can share hardware (printers),
- You can update software on all devices at once,
- You can communicate across the network easily (email),
- Your accounts can be stored in the server, so users can log in, prevents other from entering the network.
What are the drawbacks of a network?
- They can be expensive,
- Networks can be vulnerable to hacking and malware,
- Some networks are dependant on servers or specific machines, if they go down the whole network will not operate properly,
- Difficult to manage and need employ specialist staff.
What are the advantages of using Ethernet?
- Cheap,
- Fairly easily to terminate,
- Quite long distance (100m),
- Can bend around, unlike fibre optic,
- Have decent bandwidth,
What are the advantages of using fibre optic?
- Larger bandwidth,
- longer transmission distances,
- Lighter,
- Harder to tap,
- Cheap glass can be used,
- Needs little maintenance.
What are the 4 layers in a TCP stack?
- Application layer,
- Transport layer,
- Network layer,
- Link layer.
What is a network protocol?
A set of rules followed by the network that controls the communication process.
What protocols are involved in the application layer?
- FTP
- HTTP
- HTTPS
- SMTP
- POP
- IMAP
What does FTP do (File transfer protocol)?
Controls file transfer between devices.
What does HTTP do (hypertext transfer protocol)?
Controls the accessing and receiving of web pages in the form of HTML files.
What does HTTPS do (Hypertext transfer protocol secure)?
The same as HTTP but for secure sites, for example, when doing money transactions or purchasing something.
What does SMTP do (Simple mail transfer protocol)?
Sends emails from server to server until it reaches its client.
What does POP do (Post office protocol)?
Receives the email from the sender, the contents is immediately downloaded when there is a connection between the client and the server.
What does IMAP do (Internet message access protocol)??
The same as POP but does not download the contents of the email straight away as they can be read and stored on the server using different devices.
What are the protocols in the Transport layer?
- TCP
- UDP
What does TCP do (transmission control protocol)?
Determines how data is split into packets and received by the recipient,
It also detects if the packet did not make it to the intended recipient.
What does UDP do (User datagram protocol)?
Similar to TCP but has no error detection for receiving packets.
What protocols are in the network layer?
IP
What does IP do (internet protocol)?
Identifies the location of the recipient device on the internet, routes the packet from the source through routers so it can get to this device.
What is in the Link layer?
Ethernet.
What does the Ethernet do?
Links the device to the network.
What is the function of the Application layer?
- Where applications such as web browsers and email clients operate,
- Data is being encoded so that it can be understood by the recipient device,
- An appropriate header is given to the data then it is sent to the next layer.
What is the function of the Transport layer?
- Sets up a connection between the host and the recipient and agrees on settings such as packet size and language,
- Divides data into packets and gives them a packet number so the packets know what order to decode back into,
- TCP is in charge of sending the packets and making sure they get to the desired device.
What is the function of the Network layer?
- Gets the address for the packets destination,
- Attaches this information to the packets to route them to the right server.
What is the function of the Link layer?
- MAC address is used to send the packet from the node to the desired device,
- If two packets are sent at once, they wait for a random amount of time and then gets sent,
- Revives packets for the device.
