Ip addressing. Data-link layer

2. 
   1)
   

manages data exchange.

Transport.
IP addressing.
Data-link layer.

2.b (i)
Protocols are rules by using which data is send and received. Also connects devices to send and receive.

b.(ii)
SMTP // Simple Mail Transfer Protocol
Sends emails
Used in mail servers

3.

Backbone or single cable

Computer


A bus network topology is a linear network configuration where all devices are connected to a common transmission medium (the bus), usually a single cable. Data is transmitted along the bus in both directions and all devices connected to the bus receive the transmission.
Star topology:

Computer

Switch, router or hub

A star network topology is a central network configuration where all devices are connected to a central hub, switch or router. Each device has its own dedicated point-to-point connection to the central device, and data is transmitted only between the central device and the intended recipient.
2(a)
manages data exchange
Handles packets
Internet layer
Data-link layer
2(b)
SMTP Simple Mail Transfer Protocol
Used to send emails.

3(a)

Backbone or single cable

Computer
A bus network topology is a linear network configuration where all devices are connected to a common transmission medium (the bus), usually a single cable. Data is transmitted along the bus in both directions and all devices connected to the bus receive the transmission.
(b)
Data is transferred through one cable as a frames. Ethernet can’t be used by WIFI.
2(a)
Application
Transport
Network
Data-link
2(b)
HTTP- protocol that transfers HTML files.
FTP- used to transfer files
POP3-used in mail servers to receive and download emails.

3(b)
CSMA/CS- carrier sense multiple access with collision detection.

Before sending file device listens if line is idle. If line is than sends file. If collision detected device sends jam signal then waits random time and resends file.

2(a)
Application layer

Transport layer
Network layer
Data-link layer
2(b)
TCP- Transmission Control Protocol. Connects two devices and ensures safe transmission of data.
IP- Internet protocol. Works at internet layer.