1.1 Networks and protocols Flashcards
What is a network?
When two or more computers (nodes) are connected (wirelessly or wired) to each other used agreed protocols to communicate
What is are network protocols?
A set of rules that govern how data is transmitted on a network
What are the two server types?
Client Servers (CS)
Peer to Peer (P2P)
What is a Client Server?
A network where different types of servers control the network and the clients (computers) send requests to use services and resources of these more powerful servers via a LAN or WAN
What us a Peer to Peer server?
A simpler network where there is no central server controlling the network, instead the peers (nodes) are connected to one another and share/ access necessary recourses. Access rights to resources and services are authorised by setting sharing permissions on each computer. They can also download separate parts of a big file to improve download speeds
What are the advantages and disadvantages of a Client Server?
Advantages
- Faster at processing tasks
- Can manage very large networks
- Easy Access to central data
Disadvantages
- If the server/ cable fails no user can continue to work
- More expensive and complicated to set up due to hardware and software
- Requires specialist personnel to manage systems
What are the advantages and disadvantages of a P2P server?
Advantages
- Less vulnerable to central server crashes
- Simple to set up and maintain
- Initial start up cost is less and the operating systems are less complicated
Disadvantages
- Slower at processing tasks
- Only works well on smaller networks (e.g. <15)
- Security and backup are not centralised and are difficult to manage
What are the network protocols to know?
TCP/ IP - Transmission Control Protocol/ Internet Protocol
FTP - File Transfer Protocol
DHCP - Dynamic Host Configuration Protocol
HTTP - Hyper Text Transfer Protocol
SMTP - Simple Mail Transfer Protocol
IMAP - Internet Message Access Protocol
UDP - User Diagram Protocol
What is UDP?
- User Datagram Protocol is an alternative transport layer to TCP
- It sends messages instead of data packet which is much faster and has lower-latency.
- Therefore, it is used in time-sensitive transmission such as for gaming or video calls
- But can be unreliable as it does not setup a pathway before transmission
Uses messages, low-latency, less reliable (no pathways)
What is TCP?
A protocol that slits data into data packets that are routed across a network and puts together at the end using the sequence number.
It adds reliability to packet delivery by adding a destination address, source address and error check so the packet will be sent to the source if an error occurred.
What is FTP?
A protocol that governs the transfer of files across the internet between the server and client
What is DHCP?
Dynamic Host Configuration Protocol automatically assigns each device in a network with a temporary network address out of available locations. Once it goes offline the address can be used by another device and can therefore change each time we use the internet.
This is how almost all people access the internet
What is HTTP?
A protocol that transfers web pages from a web server to a client computer’s web browser
What is SMTP?
Simple Mail Transfer Protocol sends and receives email messages from a client to a server
What is IMAP?
Internet Message Accesses Protocol allows email messages to be accessed from a mail sever without it being deleted (allowing it to be accessed on multiple devices).
