CJ Sarah: Our topic is, "How the Internet Works." I'm your Emcee, Sarah Edwards. Your Host tonight is Rich Wiggins, of the Internet Connection's Pro's Corner.
Rich, that's a lot to handle. Please, take us in hand and tell all!
RichWig : Be glad to! I guess if the question is "How does the Internet work?" the answer is "Not very well at all when you need it to! " :-)
CJ Sarah: LOL, Rich, too true--glad you made it!
RichWig : But leaving aside glitches and grumbles, tonight we're going to talk about the pieces and parts that make up the Internet. As always, we would love to have questions and comments from those in the audience.
CJ Sarah: Ahh, I think we have some--let me look, Rich!
RichWig : When you sit down to use the Net sometimes it may seem like it's automatic-- or automagical-- and sometimes it's just plain ornery!
I'm curious how folks in the audience perceive of the Internet -- does it work for you?
CJ Sarah: Alexi6542 wonders...
Question: HOW can I search the Internet?
CJ Sarah: Ahh, that qualifies, I think!
RichWig : Ahh, probably the most important question there is!
Tonight I wanted to head more towards the area of how the bits and bytes move around on the Internet, not so much as to how to use it, but we'll take all questions!
How to search depends on what you are looking for.
Increasingly, people are looking for things on the World Wide Web. There are a number of search services out there, such as WebCrawler (owned by AOL!) and Lycos and Alta Vista. These are great ways to look for a particular document that contains a given word or set of words somewhere within. So if you went to http://altavista.digital.com and filled in the blank, you'd end up with all the docs that contain whatever you typed in.
CJ Sarah: DMcdan186 would like to know...
Question: Can you describe the addressing scheme for the net? What are all the // and @@ symbols?
RichWig : Good question! Sometimes it seems like computer software designers carefully aim for the far reaches of the keyboard.
The use of the "at" sign, as in wiggins@msu.edu, is commonly found in e-mail addressing. I'm sure whoever came up with the scheme literally had in mind "user at host" as user@host-- picturing Joe User sitting at UCLA or Carnegie Mellon or any other early Arpanet site.
As for the "slash slash" (//, which spawned a terrible OJ joke which I will not repeat here tonight!) Tim Berners-Lee, the inventor of the World Wide Web, is responsible for that one.
It's http:// because: http = HyperText Transfer Protocol.
The colon (:) is a separator from the protocol type (of which there are several besides http).
The // is the part that really makes the least sense! On the Apollo file system, which is what Berners-Lee ran under at Cern, where he invented the Web, a "double slash" was an absolute reference to the root directory on the file server. Many folks wish it was a single slash.
CJ Sarah: Ahh! I just though he had a screen that slanted to the right!
RichWig : Note that some browsers, such as Netscape, allow you to omit the preamble entirely. So, http://www.aol.com becomes www.aol.com.
Which seems friendlier to you?
CJ Sarah: Rich, WKish8868 would like some help in understanding, "Why does the net seem slow one day and very fast the next day?"
RichWig : Hah! I wish I knew!
I can tell you this--Murphy is there ready to wreak havoc when you need the bits to get from here to there.
CJ Sarah: Ah, the famous Murphy of Murphy's Law--if it can go wrong, it will, eh?
RichWig : Actually, this is the place where "information superhighway" is THE right metaphor!
Imagine you have an Interstate highway right next to your door. Some days all traffic moves at 70 miles per hour. Other days there are traffic jams, and no cars move at all.
Well, on the Internet, you have a bunch of links to worry about. Wherever you are dialing into--and from--there is a series of several hops (usually) over long distance lines, and then a server at the remote end. Well, if any of the intermediate hops is busy, your bits slow down. If the server is busy, you don't get a quick reply, and so forth.
CJ Sarah: Now we have a point from E Z DININ, "I've seen some sites (usually foreign) that use FTP:// and they operate identically to the familiar HTTP:// - what's up with that?"
RichWig : Good question! If a site is running a "native" Web server, then it is ready to talk the HyperText Transfer Protocol. HTTP is a surprisingly simple set of rules for how a server talks to your "client" program on your desktop. You can in fact connect to an HTTP server "manually". Sometime try doing a Telnet to a well-known Web server at port 80, then try typing GET / .and see what happens.
Well, some sites are only running FTP "daemons" and for whatever reason don't have true Web servers that speak HTTP. So this is a "poor man's" way of delivering HTML documents nonetheless.
CJ Sarah: Here's one to which there may be no answer! Avacado96 asks, "How many super computers are needed to run the Internet?"
RichWig : Would you believe zero?
CJ Sarah: Ohhhhhh, that's a VERY big number!
RichWig : There *are *a number of super computers connected to the Internet. In fact, the NSFnet backbone--which was our national set of main trunks on the Internet until last year--was created so that people could connect to supercomputer sites from universities.
But the servers that deliver data to you are very seldom supercomputers or even mainframes. In many cases they are $20,000 boxes or less.
MANY of the Web servers out there are Pentium-class machines, maybe running Windows NT, maybe running a public domain Unix. And Macs are used as servers as well.
Other pieces of hardware known as "routers" are an important part of the puzzle, getting the bits on the right long-distance links REAL FAST. So these are very powerful computers in their own right-- but not supercomputers.
CJ Sarah: Rich, Imnick288 says, "Rich, i heard that the Internet today is like an old country road, compared to the future --what does the future hold?"
RichWig : Oooh! I have been declared "unqualified" to tell you what the future holds! If I knew, I would've bought Netscape stock at $28!!!
CJ Sarah: What, Rich? Say not so!
RichWig : Seriously, it holds several things--faster connections all the way to your desktop, using ISDN, cable modems, and newer digital pipes. It holds more and more multimedia.
Our text-mode chat we're doing right now will give way to audio-enhanced, and graphics-enhanced, discussions, and then eventually full-motion video.. It will hold more interactivity, as more and more people write Java scripts. It will hold chaos with billions of URLs on the World Wide Web. And I fear it'll hold censorship in some form. :-(
CJ Sarah: DMcdan186 would like to understand, "Each installation maintains their own server? Who maintains the routers?"
RichWig : Well, it's sort of like the global telephone network. In the US, we have a bunch of long distance phone carriers, and a bunch of local carriers (mostly Baby Bells) and somehow they are all woven together.
In general, every major organization or company that establishes a presence on the Net does run its own server. But there is a major market for the business of running servers on behalf of people.
For instance, one major auto company has its Web server in Ann Arbor Michigan, where the Merit organization is located next to some very fast leased telephone lines. The routers are maintained by each of the Internet Service Providers that own 'em. And your bits may flow through the offices of several service providers to get from your desk to the remote server and back.
CJ Sarah: Regarding how the net keeps growing, Fred from AACS asks about increasing capacity, "With all the multimedia going onto the net, is there a reasonable plan to increase capacity?"
RichWig : Fred, is that the Ann Arbor Computer Society? See you in a week when I speak there.
RichWig : Well, I think it's certain that everyone who owns Internet links has to consider when the next link upgrade takes place.
To stick with a Michigan example, Michigan State had a pair of "T1" phone lines to Ann Arbor until last September-- that's a total of 3 megabits per second. Then we upgraded to a single "T3" line, at 45 megabits per second, and we needed to! Our T1 lines were becoming saturated.
The more multimedia we put through the pipes, the bigger the pipes we will need.
CJ Sarah: Rich, RoberNDC wants to know, "How does a Web Browser know where to look for a particular topic? Can you explain how they work?"
RichWig : Well, to get the nomenclature nailed down--a Web browser looks EXACTLY where you tell it to, in one of two ways: by clicking on a hyperlink in a document, or by selecting "Open URL" and typing in the URL.
In the former case, the author of the document has supplied the URL which corresponds to the words you see in blue (or highlighted) for each hyperlink.
A perverse author could put up a page in which the blue link to the Louvre in fact corresponds to the URL for Penthouse magazine, but most of them don't!
Now, I think you may be asking about search services like Lycos. They are a whole 'nother matter. They have huge indexes of all the documents they can find, and they are constantly rebuilding those indexes, usually overnight when we are asleep.
CJ Sarah: Cyberwook would appreciate understanding, "Why is newsgroups so confusing to join?? I point & click for an hour and just go in circles!)
RichWig : Wook, there are lots of different "news readers" out there, and different folks have different preferences for which tool they use.
It becomes quite religious for some "power users" of Usenet. "What??? You are using "rn" instead of Tin?" they might say. Their claim would be that Usenet isn't hard to use, but that some news readers are better than others.
There are several thousand news groups, and many megabytes of data flow through Usenet each day, so no one tool can provide the instant vector to the exact discussion you want. Besides, Usenet is so chaotic, there is no perfectly on-topic group.
Have you tried out Deja News? It's a great way to search Usenet.
CJ Sarah: DMcdan186 has another one for us...
Question: A recent article in Wired mentioned fast traffic capabilities over regular phone lines. Have you heard of this? Do you have a comment?
RichWig : Yes, I missed the Wired article, but I keep hearing about it. (Does anyone else buy Wired and then never read it?????)
CJ Sarah: LOL, Rich!
RichWig : As I recall it's something AT&T is rumored to have in the labs. A very fast digital communications scheme that works over conventional phone lines, requires very low cost investment on your premises, and puts ISDN in the dust bin.
I dunno. Could be for real, or it could be some over-zealous folks are taking lab results and claiming we can put them in the field when it's not really practical. This biz definitely involves amazing leaps in technology, so I can't be TOO skeptical.
Now, let me put on my old codger hat. Why, I remember back in the 70s, when a Vadic 1200 baud modem was an amazing thing, and AT&T claimed it was impossible to move data that fast over an analog line!
Do you realize that each new generation of modem has been claimed to be "as fast as we can go over a dialup phone line?"
CJ Sarah: Rich, I guess I need to know more about the Internet than I realized, Silence 13 asks, "Is Einstein's theory in anyway connected to the concept of a late train in the Paris Metro?"
CJ Sarah: I'm sure the Internet is in there, somewhere!
RichWig : Depends. Are you expecting to meet a relative on that train? And is it a twin?
CJ Sarah: Oh, no, not creeping relativity again!
RichWig : Actually, I will parry with a REALLY NEAT example of the Internet and subways, and Paris. There is a service where you can look at a map of the Paris subway, and click on a starting point, and then a destination, and it will tell you what trains you need to take to make that journey.
But what's neat is the author has set up a way for people around the world to upload train schedules for their locale into his server. So you can go to Paris over the Web and find out which trains to take in Boston, for instance.
I think that is the ultimate example of the global power of the Internet. I can make my software in Paris work with your data in Boston to serve a visitor coming in from Vancouver.
CJ Sarah: Rich, on another note, E Z DININ says, "Rich, tell us about ATM. Also, can you cover national versus regional Net providers?"
RichWig : ATM stands for Asynchronous Transfer Mode. It's one of several schemes for moving data at high speeds. What's different about it compared to say, Ethernet, is that ATM moves data in very small chunks called "cells" and it moves them very fast, say over fiber. But ATM works well for both high-speed local networks and for longer hauls; and it's well suited to real-time applications.
National versus regional is once again similar to phone companies. Every company in the biz decides how it wants to position itself. We also have a lot of one-town, ma-and-pa services providers.
I know of one city where the newspaper is a service provider (Raleigh NC) and another where the TV station is (Huntsville AL). So it's a mix of small medium and large companies each carving out territory. And in many cases they rent bandwidth from one another. In some cases, a national provider will work with a regional one to serve as its "Point of Presence."
CJ Sarah: DMcdan186 asks, "What source would you recommend for learning more?"
RichWig : Pro's Corner!
RichWig : Seriously, the Net itself is a good place to learn. There are some good books on the history and workings of the Net, such as The Internet System Handbook.
(Can I plug my own book here?)
CJ Sarah: LOL, it's your show, of COURSE you can!
RichWig : Check out The Internet for Everyone: A Guide for Users & Providers, which is even more long-winded than I am here.
And please, do visit us in Pro's Corner, every Tuesday and Thursday at 11, and on our message boards. Send me email with suggested topics for future live chats.
CJ Sarah: Whew! Rich, I fell like I DID learn ALL about how the Internet works! Thanks again, Rich Wiggins of Pro's Corner!
RichWig : Quiz at midnight :-) See y'all Tuesday!
CJ Sarah: And thanks to the many folks in the audience who sent in comments and questions! Good night, all!
