Basic Data Communication

Component data communication

1. Sender 
2. Receiver
3. Protocol
4. Medium
5. Message
6. Equipment

Component of data communication

Types of Message:

1. Text
2. Video
3. Audio
4. Image
5. Etc ...

Examples of medium:

1. Unshielded Twisted Pair (UTP).
2. Shielded Twisted Pair (STP)
3. Fiber Optic
4. Bluetooth
5. Infrared
6. Wireless
7. Etc..

Equipment consists of:

1. Computer
2. Bridge - Device filters data traffic, reduce the amount of traffics on a LAN by dividing into 2 segments.
3. Router - A device that forwards data  packets along network, perform the data "traffic directing" functions.
4. Hub - Commonly used to connect segments on LAN, serves simply as a conduit for the data, enabling data to go from one device (or segment) to another.
5. Switch - Device that filters and forwards packets between LAN segments.
6. Modem - Modulate outgoing digital signals from a computer or other digital device to analog signals for a conventional cooper twisted pair telephone line and demodulates the incoming analog-signal and converts its to a digital signal for the digital device.

Switch VS Hub

Hub 

Pass on traffic to network regardless of the intended destination; the PCs which the packets are sent use the address information in each packet to work out which packets are meant for them.  

Switch 

Control the flow of the network traffics based on the address information in each packet. A switch learns which devices are connected to its network and forwards on packets to the appropriate port only.

Switch VS Bridge 


Bridge
Has only two ports and divides a collision domain into two parts. All decisions made by a bridge based on MAC or layer 2 address addressing. A bridge will create more collision domain.


Switch
A fast multi-port bridge. Rather than creating two collision domains, each port creates its own collision domain.