Computer Newtork

Network Protocol

•Computers commutate with each other with network protocols

•Protocols are rules governing how machines exchange data and enable effective communication

•Ex

•When you call somebody, pickup the phone ensure there is a dial tone, and if there is then dial the number

•When driving your car follow obey the rules of the road

•Physical protocol : describes the medium (wiring), the connections (RJ-45 port), and the signal (voltage level on a wire)

•Logical protocol : software controlling how and when data is sent and received to computers supporting physical protocols

•Example common TCP/IP suite of protocol

         •Web Communication : HTTP, HTTPS

         •E-mail : POP3, SMPT, IMAP

         •File Transfer : FTP

The osi model

•OSI (Open System Interconnection) reference model

        •A conceptual framework showing us how data moves throughout a network.

                   Why was it developed?

•Created to give us a guide to under how network operate

•It is only a reference model, so don’t get wrapped up in the details.

•It is not implemented in the real world, TCP/IP is.

The osi model stack

It’s divide into 7 layer

•Upper layers (host layers)

•Handled by the host computer and perform application-specific functions.

•data formatting

•Encryption

•connection management.

•Lower layer (media layers)

           •Provide network-specific functions

                   •Routing

                   •Addressing

                   •Flow control

The osi model visualized

OSI Comunication

Osi model benefits

•Reduces Complexity

•It breaks network communication into smaller, simpler parts

•Standardizes Interface

•It standardizes network components to allow multiple vendor development and support

•Facilitates Modular Engineering

•It allows different types of network hardware and software to communicate with one another

•Ensures Interoperable Technology

•Prevents changes in one layer from affecting the other layer, allowing quicker development

•Accelerates Evolution

•Provides for effective update and improvements to individual components without affecting other components or having to rewrite the entire prototcol