What are the 4 mains things any electrical communications process requires?
- The source of information
- A transmitter to conver the convert the information into suitable data signals for the communications channel
- A communications channel
- A recipient to be able to convert the data back into its original information
What are the 3 different types of physical communications media?
- Twisted Pair
- Coaxial
- Fibre Optic
Explain the features of Coaxial cables
- Low bandwidth
- Lowest cost
- Can be easily interfered with
- Tansports data via electrical signal
Explain the features of Twisted Pair cables
- Electrical signal transmission
- Medium Bandwidth
- more expensive that coaxial
- not as easily interrupted as coaxial
Explain the features of Fibre optic cables
- Use light rays for transmission of data
- Not affected at all by magnetic interferance
- High bandwidth
- Quite expensive
What are te 4 layers to Network protocols
- Application
- Transport
- Network
- Data Link
Describe the purpose of the Application layer:
Give 3 protocols used in this layer
- Provides access to emails and files across the IP network (its like the package itself)
- HTTP, SMTP, POP
Describe the purpose of the transport layer and 2 protocols used
- Resposible for breaking the data/ message into packets and labelling them so they can be reassembled later
> Sets up the communications between the reviever and recipient - TCP, UDP
What are the differences between TCP and UDP?
- TCP is connection-oriented; UDP is connectionless
- UDP speed is faster
- TCP checks for errors and resends data packets if necessary; UDP does not
- Data travels in order for TCP; UDP packets are not ordered
describe the purpose of the network layer and the protocol involved
- Responsbile for management of adresses for both source and recipient (finding the best route to take)
- IP protocol
- Resonsible for actually transmitting and recieving the data (like the van that carries the package)
- ETHERNET, Wifi
What are the 2 layers involved in TCP/IP protocol?
- Transport and Network Layers
What is the advantage of using layers for network protocols?
- Layers are self-contained
> This means each layer can operate individually without effecting functionality of other layers
What is FTP and what does it do?
- File Transfer Protocol
- Sending or recieivng files from a server to another location
What is the difference between IMAP and POP
- POP downloads the entire message
- IMAP Only downloads message header and is kept on the network for usage
What is SMTP?
- Simple Mail Transfer Protocol
- Email protocol used to transfer emails between email servers
Describe the process of sending emails
- Client sends email through SMTP to mail server
- Mail server sends email though internet through SMTP
- This is sent to the other mail server through SMTP
- Reciever aquires email by downloading it rhough POP or IMAP
