Diagram how does the internet work

In any case, if you are connected to the Internet, your computer has a unique IP address. It's called ping , probably after the sound made by older submarine sonar systems. If you're using a flavor of Unix, get to a command prompt. Type ping www. The pinged computer will respond with a reply. The ping program will count the time expired until the reply comes back if it does.

Also, if you enter a domain name i. More on domain names and address resolution later. Protocol Stacks and Packets So your computer is connected to the Internet and has a unique address. How does it 'talk' to other computers connected to the Internet? An example should serve here: Let's say your IP address is 1.

The message you want to send is "Hello computer 5. Obviously, the message must be transmitted over whatever kind of wire connects your computer to the Internet. Let's say you've dialed into your ISP from home and the message must be transmitted over the phone line. Therefore the message must be translated from alphabetic text into electronic signals, transmitted over the Internet, then translated back into alphabetic text. How is this accomplished?

Through the use of a protocol stack. Every computer needs one to communicate on the Internet and it is usually built into the computer's operating system i. Windows, Unix, etc. Hardware Layer Converts binary packet data to network signals and back. If we were to follow the path that the message "Hello computer 5.

If the message to be sent is long, each stack layer that the message passes through may break the message up into smaller chunks of data. This is because data sent over the Internet and most computer networks are sent in manageable chunks. On the Internet, these chunks of data are known as packets. Each packet is assigned a port number. We need to know which program on the destination computer needs to receive the message because it will be listening on a specific port.

This is where each packet receives it's destination address, 5. Now that our message packets have a port number and an IP address, they are ready to be sent over the Internet. The hardware layer takes care of turning our packets containing the alphabetic text of our message into electronic signals and transmitting them over the phone line. On the other end of the phone line your ISP has a direct connection to the Internet.

The ISPs router examines the destination address in each packet and determines where to send it. Often, the packet's next stop is another router. More on routers and Internet infrastructure later. Eventually, the packets reach computer 5. As the packets go upwards through the stack, all routing data that the sending computer's stack added such as IP address and port number is stripped from the packets.

When the data reaches the top of the stack, the packets have been re-assembled into their original form, "Hello computer 5. But what's in-between? What actually makes up the Internet? Let's look at another diagram: Diagram 3 Here we see Diagram 1 redrawn with more detail. The physical connection through the phone network to the Internet Service Provider might have been easy to guess, but beyond that might bear some explanation.

The ISP maintains a pool of modems for their dial-in customers. This is managed by some form of computer usually a dedicated one which controls data flow from the modem pool to a backbone or dedicated line router. This setup may be refered to as a port server, as it 'serves' access to the network. Billing and usage information is usually collected here as well. From here the packets will usually journey through several routers and over several backbones, dedicated lines, and other networks until they find their destination, the computer with address 5.

But wouldn't it would be nice if we knew the exact route our packets were taking over the Internet? As it turns out, there is a way This one is called traceroute and it shows the path your packets are taking to a given Internet destination. Like ping, you must use traceroute from a command prompt.

In Windows, use tracert www. From a Unix prompt, type traceroute www. Like ping, you may also enter IP addresses instead of domain names.

Traceroute will print out a list of all the routers, computers, and any other Internet entities that your packets must travel through to get to their destination.

If you use traceroute, you'll notice that your packets must travel through many things to get to their destination. Most people don't have any idea where the internet came from and doesn't matter, they don't need to.

It's sort of like asking who invented the ballpoint pen, or the flush toilet or the zipper. These are all things we just use every day we don't even think about the fact that one day somebody invented them. So the internet is just like that. Many, many years ago in the early s my partner Bob Kahn and I began working on the design of what we now call the internet. It was a Defense Department research project.

Paul Baran was trying to figure out how to build a communication system that might actually survive a nuclear attack. So he had this idea of breaking messages up into blocks and sending them as fast as possible in every possible direction through the mesh network. The government controls it. Elves, obviously elves! The people to control the Wi-Fi because then no Wi-Fi, no internet. T-mobile, um, Xfinity, Bill Gates [pause] Right?! The first of those components is hardware.

That includes everything from the cables that carry terabits of information every second to the computer sitting in front of you. Other types of hardware that support the Internet include routers , servers , cell phone towers, satellites, radios, smartphones and other devices.

All these devices together create the network of networks. The Internet is a malleable system -- it changes in little ways as elements join and leave networks around the world.

Some of those elements may stay fairly static and make up the backbone of the Internet. Others are more peripheral. These elements are connections. Some are end points -- the computer, smartphone or other device you're using to read this may count as one.

We call those end points clients. Machines that store the information we seek on the Internet are servers. Other elements are nodes which serve as a connecting point along a route of traffic. And then there are the transmission lines which can be physical, as in the case of cables and fiber optics, or they can be wireless signals from satellites, cell phone or 4G towers, or radios. All of this hardware wouldn't create a network without the second component of the Internet: the protocols.

Protocols are sets of rules that machines follow to complete tasks. Without a common set of protocols that all machines connected to the Internet must follow, communication between devices couldn't happen. The various machines would be unable to understand one another or even send information in a meaningful way.

The protocols provide both the method and a common language for machines to use to transmit data. We'll take a closer look at protocols and how information travels across the Internet on the next page. You've probably heard of several protocols on the Internet. For example, hypertext transfer protocol is what we use to view Web sites through a browser -- that's what the http at the front of any Web address stands for.

If you've ever used an FTP server, you relied on the file transfer protocol. Protocols like these and dozens more create the framework within which all devices must operate to be part of the Internet.

What do these protocols do? At their most basic level, these protocols establish the rules for how information passes through the Internet. Without these rules, you would need direct connections to other computers to access the information they hold. You'd also need both your computer and the target computer to understand a common language. You've probably heard of IP addresses. These addresses follow the Internet protocol. Each device connected to the Internet has an IP address.

This is how one machine can find another through the massive network. The version of IP most of us use today is IPv4, which is based on a bit address system.

There's one big problem with this system: We're running out of addresses. The result was IPv6, a bit address system. That's enough addresses to accommodate the rising demand for Internet access for the foreseeable future [source: Opus One ].