Not knowing your level of expertise, I’ll put it is simply as I can.
Take a phone conversation (Voice), turn the sound into digital data, put the address of the other end of the conversation on the data, and send it out over the internet along with all the other data (Over Internet Protocol). The data finds it’s way to the other end, gets turned back into sound, and becomes the other end of the conversation. The principle is simple, the more difficult part is in the digitizing standards for compatibility, address assignment, routing, error recovery, etc.
The postal analogy, my favorite for teaching packet data systems (like the internet), goes like this:
You want to send a book to a friend (your data), but the only method you have is sending letters. You take out each page, put it in an envelope, address it, (packetize it) and mail it. You don’t even have to put them in the same mail box. The postal service (the network) reads the address on the envelopes and routes them all to the same destination (routing), although possibly not in the same order. Your friend receives the envelopes, takes out the pages, puts them back in order, and reassembles the book.
The postal service worries about all the details like finding the location of the address, finding the best way to get there to avoid road closures and traffic jams, whether to fly it or drive it, how many letters they can fit in which size truck, etc.
Now, imagine it all happens so fast that you can do this with pieces of a conversation…
Post written by Martin Hewes http://www.linkedin.com/pub/martin-hewes/30/142/a21
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