1.1 Networking Fundamental
1.1.1 Definition of Network:
a collection of hardware components and computers interconnected by communications channels that allow sharing of resources and information.
A Map Representation of WWW of Wikipedia
1.1.2 OSI Model:
The "Open Systems
Interconnection Reference Model is the effort at the International
Organization for Standardization. It is a prescription of
characterizing and standardizing the functions of a communications
system in terms of abstraction layers. Similar communication functions
are grouped into logical layers. An instance of a layer provides
services to its upper layer instances while receiving services from the
layer below.
An Illustration of the Functioning of OSI Model:
1.1.3 Description of OSI layers:
| OSI Model | ||||
|---|---|---|---|---|
| Data unit | Layer | Function | ||
| Host layers |
Data | 7. Application | Network process to application | |
| 6. Presentation | Data representation, encryption and decryption, convert machine dependent data to machine independent data | |||
| 5. Session | Interhost communication | |||
| Segments | 4. Transport | End-to-end connections, reliability and flow control | ||
| Media layers |
Packet/Datagram | 3. Network | Path determination and logical addressing | |
| Frame | 2. Data Link | Physical addressing | ||
| Bit | 1. Physical | Media, signal and binary transmission | ||
1.1.4 Example of Protocol:
