Sorting apples

If you've been following along with our series on networking you now understand that regardless of how data gets out of your computer to your DAC - USB or over a network - the path it takes is a shared one used by more than just the music we want to send. In fact, USB stands for Universal Serial Bus and the very name itself is a clue for us to understand this shared architecture: the last two words specific keys. "Serial" refers to a single conduit where everything marches along in series, one followed by the other. "Bus", represents a group of items together; the actual word derived from "Omnibus" which, in literary terms, refers to a book of collected stories or volumes. The point is that USB is a single shared path in the same way that our network is and all the "traffic" on either the network or the USB is traffic sharedwith many others. I am keeping us focused on the shared nature of traffic on these exit paths from your computer because it is this shared quality that is the essence of how a computer and a network works - and once you get your arms around how and why the computer is such a sharing and caring machine, the rest will be child's play. Have you ever seen how a machine sorts apples? Picture a long single conveyor with thousands of apples traveling down the path in single file. Along the way, apples leave the path - like cars exiting the freeway - while others continue on their way and leave by different exits. At the end of the conveyor there are no apples left. The apples get off at various exits because of their size or weight: large ones first, then the next size down, finally ending with the smallest apples. In this way, the farmer can simply dump a basket of multiple sized apples into a hopper and, though the apples are mixed up, each finds its way to where it needs to go following a shared path. Think of this as the apple network where many different types of apples can all journey down the same path; yet each has a different final destination. This analogy isn't too far off from how data travels down our shared paths but, instead of apples, we have another enclosure called a packet. These packets are data enclosures and identified not by their size but with little "notes" pinned on their "shirts" in the same way that a line of grade school children can be sorted out by their teachers: using these little name tags. Tomorrow, the Packet Racket.