Networking Basics OSI- Reference Model Flashcards
Network Types
WAN - Wide Area Network - Covers large Geographical Area
LAN - Local Area Network - Covers a small geographical area compared to WAN. (Local Area 10 KM approx.)
OSI layer
1 - Physical layer
2 - Data Link Layer
3 - Network Layer
4 - Transport Layer
5 - Session Layer
6 - Presentation Layer
7 - Application Layer
Physical Layer Example
Voltages, frequencies, connectors, cables, modulation, etc.
Sub- layers of Data Link Layer
Media Access Control (MAC) and Logical Link Control (LLC)
Data Link Layer Example
Layer 2 Devices such as Switch, Hub, Bridge
Function of layer 2
Provide rules for framing, converting electrical signals to data, error checking, physical and medial access control (MAC) addressing
Function of layer 1
Converting data to electrical signals for Copper medium, frequencies for wireless medium and light for fiber mediums.
Network Layer Example
Routers
Function Of Layer 3
Routing the data between networks. The protocol used now is IP, initially IPX, AppleTalk
Transport Layer Example
TCP
UDP
Function of layer 4
responsible for end-to-end communication, error recovery, and flow control.
Session layer Example
Browser
Function of Layer 5
The mechanism for opening, closing, and managing a session between end-user application processes.
Example of Presentation Layer
ASCII Codes
The function of Layer 6
Deals with data format conversion and possibly with encryption and security
Responsible for the delivery and formatting of information to the application layer for further processing.
Example of Application layer
FTP, Modbus, Profinet, DNP3, BACKnet, Ethernet/IP, HTTPS, DNS, email etc.
Function of layer 7
User Applications. It does not include the Operating system or user software applications such as word processing.
