The data, conversations, or pictures of your cute pet you send or view across this web of connections all have to be packed up for travel to the various addresses linked through the strands of the web. Where IP addresses are the street addresses and cables of copper, strands of glass, or the air waves themselves are the roadways you still have to get those ideas of yours you so diligently produced on that machine we call a computer into a format ready for travel.
To help understand the process of packing up those electrons Network Admins and Gurus have developed two models illustrating what happens to the data we see on the screen to the point of the 1’s and 0’s being transmitted back and forth across the web or for that matter any network. The two models are called the OSI (Open System Interconnection) model and the TCP/IP model which we touched on in the article Internet Protocol: Street Address of the Internet. Continue reading Protocol Data Unit: A Suitcase for Electrons
The TCP/IP model defines the four communication functions that protocols perform. TCP/IP is an open standard, which means that one company does not control it.
– Network Fundamentals, CCNA Exploration Companion © 2008 Cisco Systems Inc.
TCP/IP: Transport Control Protocol/Internet Protocol
This quote from a Cisco CCNA textbook gives the industry definition for TCP/IP, but it does little to help us understand how the protocol actually delivers electrons of data across that etheric gulf woven of links known as the World Wide Web to our eyes and ears in the comfort of our own home or business.
To help understand the following section of this article think of the Internet Protocol addresses as street addresses identifying each and every resource networked.
The country designation in the address is a large network which can be divided up into subnets which are then represented by the state designator of your address. The resulting subnet is then divided up into smaller subnets to represent the city and divided into what we can consider our “street” subnet. It is in this subnet that our Public IP address which would represent our house’s or place of business’s address number. Continue reading Internet Protocol: Street Addresses of the Internet