Protocols Flashcards
Name 3 forms of communication media
- Coaxial cable
- Fibre-optic cable
- Micro waves
What signals do copper wires carry?
Electrical signals
What signals do fibre-optic cables carry?
Light signals
What is a protocol?
A set of rules that govern how communications on a network should be formatted and what data they should include
Name 2 advantages of wireless connectivity
- No need for cables
2. Allows users to use their own device
Name 2 disadvantages of wireless connectivity
- Data transmission speeds are slower
2. Walls and other objects could affect performance
Name 2 advantages of wired connectivity
- Faster than wireless
2. Not easy to intercept or eavesdrop on data
Name 2 disadvantages of wired connectivity
- Expensive to install
2. Requires many cables
How many bits is 1 bps?
1
How many bits is 1 kbps?
1 * 10^3
How many bits is 1 Mbps?
1 * 10^6
How many bits is 1 Gbps?
1 * 10^9
What is bandwidth?
The amount of data that can be carried on a network in a given period of time
What is SMTP?
Used when sending email from client to server and then server to server until it reaches its destination
What is POP3?
- used for retrieving email from an email server
- all emails are downloaded when there is a connection between client and server
What is IMAP?
emails can be read and stored on the message server without downloading it, which means that the emails can be read from different devices rather that just being downloaded to one
What is HTTP?
Used when sending and receiving data between web browsers and web servers
What is HTTPS?
data sent between web browser and web server is secure by using encryption
What is FTP?
- used to transfer files over a network that uses the TCP protocol
- often used to transfer files that are too large for attachment for emails
What are the 3 things that protocols need to include?
- data formats: to ensure that data can be exchanged consistently and correctly
- address formats: to identify senders and recipients and to ensure that data goes to the right places
- routing: to provide the right information so that data can flow through the networks correctly
What is a TCP/IP protocol?
a stack of protocols that allows a computer to communicate across a WAN
What are the 4 layers of the TCP/IP model?
- Application
- Transport
- Internet
- Data Link
What is the purpose of the Application Layer?
- provides service to applications such as web browsers and email clients
- where requests are made to web servers or emails are sent
What is the purpose of the Transport Layer?
- divides data sent from the application layer into packets
- checks that the data sent has been received
- notifies sender that data has been received
What is the purpose of the Internet Layer?
-adds the source and destination IP addresses to the data and routes it to the recipient computer
What is the purpose of the Data Link Layer?
-uses network specific protocols to ensure correct transmission of data through the local network
What protocols are used at the Application Layer?
- FTP
- HTTP
- HTTPS
- IMAP
- POP3
- SMTP
What protocols are used at the Transport Layer?
- TCP
- UDP (user datagram protocol)
What protocols are used at the Internet Layer?
IP
What protocols are used at the Data Link Layer?
Ethernet or Wifi protocols
How does the TCP provide a reliable connection between computers?
- ensuring that the receiving computer sends a notification that each section of the data sent has been received
- using checksums
- flow control
- ensuring that the data sent up to the application layer contains no duplicates and is in the correct order
