Section 1.3.3 Networks Flashcards
What is a network?
When a computing device is connected to another
What are the advantages of networks? (5)
- Can share files
- Can share peripherals and connections to other networks e.g. the internet
- Can access files from any computer on the network
- Servers can control security, software updates and backups
- Good for collaborations
What are the disadvantages of networks?
- Increased security risks
- Malware and viruses
- If the server fails, connections to it may not work
- Computer may run slower if there’s lots of data on the network
What are standards?
A set of hardware and software specifications that allow manufacturers to create products and services that are compatible with each other
What is a protocol?
A set of rules defining common methods of data communication
What is the purpose of the TCP protocol?
Provides error free transmission between two routers
What is the purpose of the IP protocol?
Routes packets across a WAN
What is the purpose of the UDP (User Datagram Protocol) protocol?
Communication protocol for time sensitive applications e.g. gaming or DNS lookups
What is the purpose of the HTTP protocol?
A way for the client and server to send and receive requests and deliver webpages
What is the purpose of the HTTPS protocol?
A way for the client and server to send and receive requests and deliver webpages
What is the purpose of the FTP protocol?
Used for sending files between computers (normally on a WAN)
What is the purpose of the SMTP protocol?
Transfers outgoing emails between servers and from email clients to servers
What is the purpose of the POP protocol?
Retrieves email from the mail server and transfers them to your device, removing them from the server
What is the purpose of the IMAP (Internet Message Access Protocol) protocol?
Keeps emails on the mail server, maintaining synchronicity between devices
What is the internet?
A collection of interconnected networks, routers, cables, satellites and other hardware spanning the world
In a home network connected via a wireless router, what is the router connected to?
The ISP (connected by fibre optic cables or telephone connection
- ISP is then connected to the DNS and other routers
What is layering?
Dividing the complex task of networking into smaller, simpler tasks that work in tandem with eachother
What are the characteristics of layering?
- Hardware and software for each layer has a defined responsibility
- Each layer provides a service to the layer above it
What are the advantages of layering?
- Reduces complexity of the task by dividing it into smaller subproblems
- Devices can be manufactured to operate at a particular layer
- Products from different vendors can work with eachother
What is the TCP/IP stack?
Set of networking protocols, consisting of 4 protocols working together
State the 4 layers in the TCP/IP protocol stack
- Application layer
- Transport layer
- Internet layer
- Link layer
What is the purpose of the application layer?
Consists of protocol rules that deal with network applications e.g. web browsers and email programs
What protocols are on the application layer?
- FTP
- HTTP
- HTTPS
- SMTP
- IMAP
What’s the purpose of the transport layer?
Sets up communication between two hosts - agree on settings e.g. language
What protocols are in the transport layer?
- TCP
- UDP
What is the purpose of the internet layer?
Addresses and packages data for transmission / routes packets across a network
What protocol is in the internet layer?
IP
What is the purpose of the link layer?
Where net hardware and connections and OS drivers are located
- Facilitates transmission of binary via any media
What happens in the application layer? (1/4)
Application uses the appropriate protocol relating to the application being used to transmit data
What happens in the transport layer? (2/4)
- Uses TCP and other conversation protocols which use port numbers to track sessions and add it to the header
- When connection = made, TL splits data into packets
- Adds to each packet: its num./sequence, total num. of packets, port num. the packet should use
What happens in the internet layer? (3/4)
- Packets go to the IL
- Adds to each packet: source IP address and destination IP address
- Routers use IP to find out where the packets are headed
What happens in the link layer? (4/4)
- Acts as a physical connection in which the packets become frames
- Responsible for adding the MAC address of the source device and destination device
What is an IP address?
A unique address hat identifies a device in the internet or a LAN
