Protocols

Question 1

HTTP

Answer 1

Hyper Text Transfer Protocol

Used by web browsers to access websites + communicate w web servers

Question 2

HTTPS

Answer 2

HTTP Secure - encrypts all info sent + received

Question 3

FTP

Answer 3

File transport protocol
Used to ACCESS, EDIT + MOVE files between devices on a network
e.g. access files on a server from a client computer

Question 4

IMAP

Answer 4

Internet Message Access Protocol

Used to RETRIEVE emails from a server

Question 5

SMTP

Answer 5

Simple Mail Transfer Protocol

Used to SEND EMAILS + transfer emails between servers

Question 6

TCP

Answer 6

Transmission Control protocol:

1. Establishes a connection between sending + receiving devices
2. Splits data into NUMBERED packets that can be reassembled out into the original data once they reach their destination
3. Communicated w receiving device to ensure all packets have been transferred correctly so missing/corrupt can be resent (confirmation sent to sending once complete)

Question 7

UDP

Answer 7

User Datagram Protocol:

• Breaking down into packets w out numbering
• read by receving device in order they arrive
• only sends packets once + doesn’t check if everything has been received
• SAVES TIME but we never know if packets went missing

Question 8

where you would use UDP or TCP

Answer 8

UDP - fast, efficient transmission e.g. live streaming as hiccup in video quality is better than delay

TCP - reliable connection e.g. downloading files as otherwise file can be corrupted + unusable

Question 9

IP

Answer 9

Establishes connections between routers + handles network trafffic

1. Unique IP address assigned to every device + added to header of each packed in Internet Layer
2. IP responsible for directing data packets to destination across Internet/IP networks using PACKET SWITCHING
3. Each Packet is sent between a series of routers - and each one reads IP address to decide which router to send packet to
4. The direction of data can change on network traffic so packets can take diff routes. Packets can also be prioritised if a router is overloaded
   - efficient as so many possible routes so they reach quick

Question 10

WIFI

Answer 10

Family of protocols mainly used in WLANS

• units sent on link layer are FRAMES not packets
• WIFI uses 2 radio bandsL 2.4 GHZ + 5 GHz
• Bands split into numbered channels that cover a small freq range
• data is encryted on WIFI (security protocols = WPA + WPA2)

Question 11

2.4Ghz + 5GHz differences

Answer 11

2. 4: greater range and better at getting through obstructions
   - channels also overlap which can cause interference

5: faster over short distances

Question 12

Ethernet

Answer 12

handles transmission of data between devices on LANS

- specifically for wired connections