Programming & Networking (MERN + Cisco + Microsoft)

OSI Model - Data Link Layer  Hello friends once again i am vasu birla for discussing about second and most overloaded layer of OSI model  it is Data link Layer Data Link Layer -  It is the second layer from the bottom of OSI layer. Some Important functions of data link are following - Framing Error Detection Physical Addressing Flow Control   . Framing -   in the physical layer PDU (protocol data unit) is bit  it means in the physical layer data comes in form of bit or 0,1 form.  but later these different bits is converted in the frames combination of some 0s and 1s  the reason behind the framing is  easy error detection , so framing of data takes place in the data link layer.   Error Detection - When each layer of OSI pass data to other layer so it include header also ,, but the only data link layer attach header and as well as trailer . There is value in this Trailer  that is known as FCS or Frame check sequence.  FCS value is a calculated value of our frame whic

OSI Model - Physical Layer  Hello Friends i am Vasu Birla and today i will discuss about first Layer of OSI model ,, Physical Layer. Physical Layer   is the layer where actual data moves physically across the networks interfaces or components.   Physical layer specify standards about physical cables, devices and connecters. Some Important functions of physcial layer are:-  Transmission Media -  Which kind of medium used to transmit data it is wired or wireless and which kind of cables and connecters are used  , and how data are sent one devices to other with wired or wireless midium these all are comes under physical layer. (We will discuss in details about every transmission medium)   Transmission mediums Encoding & Signaling - Physical layer is also responsible for encoding and Signaling function. for exam those data are in form of bits or 0 and 1 form  so how these data can be sent to other devices and  what voltage levels should be for sending data in form of Sig

OSI Model  (Open System interconnection) Hii , i am Vasu Birla and today we discuss about OSI Model, a very popular term often used in the Networking. So  What is OSI model and why it is needed  So pahle History pad lete he ,,, History of Osi -   In the 1977, ISO (International Standard Organization) made a committee for Develop a Open standard for Interconnection between the all kind of electronic devices  after that Later in 1984 ISO's committee introduce a OSI model ( Open System Interconnection Model). What does mean by OPEN   - In OSI (Open system interconnection ),,, Here Open means ,, whomever follow this Model  means  vendors , Manufactures ( IBM,apple,Microsoft, Intel )   jo bhi ho ,, if they follow this model for manufacture computer systems so, Those devices, systems can communicate to each other  whether that are from same vendor or from different Manufacturer . ( matlab yadi ye companies OSI ko follow karke apne systems banate he to wo aapas me internet se conne