#internetlayer

TCP IP Reference Model - Whenever A Computer Wants To Communicate With Another Computer, The Communication Between Those Two Computer's Should Be Good And Reliable.So We Can Guarantee That The Data Is Received Correctly.

For Example When You Want To View A Web Page Or Download A File Or Look At Email You Would Expect The Web Page Intact In Order With Nothing Missing.

Or If You Download A File,You Would Want Entire File To Be Downloaded With Missing Data In It.

This Is Where TCP Comes In. TCP Stands For Transmission Control Protocol And This Is One Of Main Protocols Used In TCP IP Network.

TCP Is Guarantee That All The Data Is Received And In Order. Because Without TCP There Some Of The Data Could Be Missing Or Out Of Order. Because If You View A Web page Without TCP Your Web Page Could Be All Messed Up.The Images Could Be Missing Or The Text Could Be Backwards And Out Of Order. Or If You Download A File, You Might Not Get The Entire File Or You Could Get A File Out Of Order Which Would Render The File Useless. So This Is Where TCP Comes In. TCP Is A Connection Oriented Protocol Which Basically Means  That It Must First Acknowledge A Session Between A Two Computers They Are Communicating. So The Two Computers Verify A Connection Before Any Communication Takes Place And It Does By Using A Three Way Hand Shake. So The First Step A Computer Will Send Message Called SYN. Then The Receiving Computer Send Back An Acknowledgement Message Telling The Sender That They Has Received The Message. And The Finally The Sender Computer Sends An Acknowledgement Message Back To The Receiver Computer.

    Once This Has Taken Place Data Can Be Delivered.   And Another Important Thing To Remember About TCP Is That It Guarantees The Delivery Of The Data. So If The Data Packet Goes Straight And Doesn't Arrive Then TCP Will Resent It.  

IP Address (Internet Protocol Address)