overview of OSI model layers:

7.Application-it is user friendly, what ever we are seeing on screen is application, internally it is converted to presentation, session, transport etc.. ex-Browser

6.Presentsation-it’s just a translation-translates data coming from application layer, name of unit exchange here is PPDU(Presentation protocol data unit)

5.Session-encryption and decryption of data, name of unit exchange here is SPDU(Session protocol data unit)

4.Transport-It is the Heart of the OSI model, it trasports data and name of unit exchange is TPDU(Transport protocol data unit)

3.Network-Data is in the form of (packets)

2.Datalink- It takes information from network and transports data to physical, everything is in the form of (frames)

  1. Physical-In physical layer everything is in the form of (bits).Finally when CPU is reading the data it is physical data, it converts bits to signals.



Links and Joints

Links are used to connect different bodies and objects.It contains nodes where u going to join with other bodies or links based on the number of nodes they are classified as Binary,Ternary,Quaternary.

  • Binary link:This link has two nodes
  • Ternary link:This link has three nodes