Communication begins with a message, or information, that must be sent from one individual or device to another using many different communication methods.
All of these methods have 3 elements in common:
- Message source or sender
- Destination or receiver
Data is divided into smaller parts during transmission ➔ Segmentation
The benefits of doing so:
Many different conversations can be interleaved on the network. The process used to interleave the pieces of separate conversations together on the network is called multiplexing.
Increase the reliability of network communications. The separate pieces of each message need not travel the same pathway across the network from source to destination
Downside of segmentation and multiplexing
Level of complexity is added (process of addressing, labeling, sending, receiving and etc are time consuming)
Each segment of the message must go through a similar process to ensure that it gets to the correct destination and can be reassembled into the content of the original message
Various types of devices throughout the network participate in ensuring that the pieces of the message arrive reliably at their destination
Sample network diagram
- Devices (PCs, intermediary devices)
- Media (Cable or wireless)
- Services and processes (Software)
In the context of a network, end devices are referred to as hosts.
A host device is either the sender or receiver
To distinguish one host from another, each host on a network is identified by an address.
Software determines the role of a host. A host can be a client, server or both
- Computers, workstations, laptops, and servers…..
- Network printers
- Voice over Internet Protocol (VoIP) phones
- Handheld devices like PDA, mobile phones…
- Cameras on a network, webcams and security cameras