As you know, the Internet is a great place to access all sorts of information! Well, how does this information actually reach you? First, the file that you want to access (for example, an e-mail message, a graphics file, an HTML file, etc.) is broken up several small chunks of data. These chunks, called packets, are then each assigned a separate number, and routed to your computer (or whichever computer the user specified it to go to). The packets don't all have to take the same route to get to the designated location. They could all take different routes, and then when all the packets arrive, the packets are combined into the file's original form, all ready for you to access!
A packet is typically 1 kilobyte in size. Sometimes, if the file is really large, there can be thousands of packets! Each of these packets will make their way individually to the destination!
A very important part of all packets is the "header." The header makes sure that the packets don't get "lost" as they're traveling through the network, and it also specifies the destination of packet. The header contains five major bits of information:
2. Destination: The opposite of the source, the destination contains the IP Address of the computer that is receiving the packet.
3. Length: This tells the length of the packet, in bytes.
4. Number: As you know, sometimes messages can be broken up into hundreds, if not thousands, of packets. The number specifies the total number of packets in the whole message.
5. Sequence: Each packet in a file is given a specific number. This number is stated in the sequence, and tells what the number of this specific packet is in relation to the other packets making up the file.
The concept of packets and packet-switching networks (networks making use
of the idea of packets) are widely used throughout the Internet, and are extremely
efficient!
1995-2001, ThinkQuest Inc.all rights reserved
