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INTRODUCTION
Hi... I'm DAwn's dog Wolf. (In Cyberspace, even an Aussie dog like me can write a Web page
like this one.)
Anyway, welcome to the 2006 Edition of the official dog Wolf techno-cultural survival
Encyclopedia to Cyber-Networking. In here, I shall try to lovingly explain each geeky Net-Word
that folks have asked me to take a shot at over the last year, two years, three years,
four years, five years, six years, seven years, eight years, nine years ten years
(1996-2006).
Some Net-Words, like "ROFL" are very easy to explain; but others, like "Domain" have started a fair number of pub brawls. Some Net-words that were very cool back in 1996 (like "Archie") have have cooled off, and I've respectfully retired them. (However, you can probably locate them languishing on one or more of my unofficial "mirror" servers... i.e., sites where folks have "borrowed" my dog Wolf definitions.) Others terms, like "Wireless Networking Diagram" and "Network Access Point" and "WiFi" and "Broadband" have rapidly become terms of endearment; and I've scurried about to add them as quickly as I possibly could.
As always, my thanks to the usual suspects (Net-gurus, professors of computer science, DAwn, DAwn's ex-boyfriends (hackers, nerds), and surely DAwn's brother, etc.) for periodically reviewing my page here and screaming at me until I more fully understand why I am an idiot. (And they wonder why DAwn plays bluegrass on the oboe.) In a few cases, I have lost my cool and asked the folks at Precise Networking Solutions to actually let me "touch" some Net-word... e.g., the chipset.
(I am totally amazed at the number of senior engineers who know precisely what a Net-word means, who can design an elegant state-of-the-art network, who know networking solutions like the back of their hand... but who cannot explain in people-words why they did what they did. In such cases, we have sat down (one of us, at least) and played Q&A... in one instance for over an hour... when I insisted that I wanted to learn wireless networking. (I am nothing if not dogged.) )
Sometimes, when someone has raised a nugget that I think is cool, but it's a little obscure and not really directly related to the subject, I'll mark it with something that looks like... IMPRESS YOUR WOMBAT--> I really look nothing at all like a wolf, save perhaps for my yellow eyes; and I do have a penchant for howling at the most inappropriate of times. And though I'm an Aussie, I have done my best to use Americanised spellings.
If YOU would like some Net-Word defined and explained, or if you'd like to elaborate on an exisiting definition of mine, feel free to contact me via the Precise Networking Solutions e-mail link at the bottom of this page, and we'll take a peek. (Think the summer of 2006 is going to set a record for the warmest and rainiest in history? Yoiks.)
Ok... let the adventure begin...
32-Bit
The operating system in a hospital is the way they like to do surgery. The
operating system on a computer is a bunch of programs and some data...
Windows and Linux are two popular operating systems.
Unlike "useful" application programs such as TurboTax (urghh), the operating system programs (and data) simply provide a warm, cozy environment for the application programs to run over... just as the furnace in my basement provides a warm, cozy environment in all the upstairs rooms in winter.
Think of your PC as a large house. The application programs each occupy one of the smaller upstairs rooms... Internet Explorer in the master bedroom, Outlook Express in the dining room, etc. But the operating system programs, they fill the whole basement.
And coming into the basement are wires from our monitor, from our cable modem's router, from our mouse, from our hard drive, and so on.
Let's say that a program who is living upstairs, like TurboTax, wants to read or write directly to our hard drive. Can he do it? Yeah, but it means that TurboTax has to add ALL kinds of extra instructions to deal with reading the hard drive. Netscape, if he wanted to read directly from our hard drive, he'd have to add all the same extra instructions.
Instead, because we have the operating system in the basement, each application program (upstairs program) simply issues a brief "call" to the operating system down in the basement when he wants to read from or write to the hard drive... or when he wants to access almost any system resources... and the operating system takes care of all the grizzly details. And as a result, our application programs are much smaller and simpler.
And because the operating system is interfacing between our upstairs application programs and our hardware, we can have lots of programs at one time accessing our hard drive... lots of programs "running" at one time... and the operating system routes the right piece of data to the correct program.
AND... because the operating system is managing all of our hardware resources, we are able to run many programs (almost) simultaneously... which keep our processor chip busier, and thus makes our computer run more efficiently... now we can do a virus scan while we are surfing the Web... in other words, the operating system allows us to "multi-task."
Now... operating systems like Windows NT/2000/XP and 95/98 and UNIX and and Mac OS are called "32-bit Operating Systems"... they can run 32-bit programs. (A bit is a 0 or a 1. Strings of bits can represent characters and numbers... like 1100 represents a decimal 12.)
32-bit programs can send and receive 32 bits of data at one time to and from your PC's hardware (like your CD ROM reader). And since today's PCs can operate on ALL 32 bits at once, 32-bit programs run faster than the older 16-bit programs.
BUT... Operating systems like DOS 3.0 and Windows 3.1 are called "16-bit operating systems"... they can run 16-bit (but not 32-bit) programs; 16-bit operating systems and 16-bit programs are pretty much a pre-1995 thing.
AND... 32-bit programs also can instantly access ALL of the real memory... all of the RAM... in modern PCs... something that 16-bit applications programs cannot do.
What is RAM (random access memory)? It's the place in your PC that your programs (or the currently running "pieces" of your programs) have to be living when they are executing; only program instructions in RAM (real memory... hardware that you can touch and that you have to pay real money for) can execute. (No, you cannot download real memory from KAZAA; you have to buy it or borrow it.)
And only DATA in real memory can be read and written by programs that are executing.
To say it another way, 32-bit operating systems like Windows 98 need processing chips (like Intel's Pentium IV chip) that can access all the RAM on your PC at once. Hence, Windows 98 will not run on the ancient Intel 80286 chip, because this chip can access only 16 Meg of RAM at once. (A Meg is slightly more than a million 8-bit strings (bytes). And a GIG is slightly more than a billion 8-bit bytes.)
IMPRESS SATURDAY'S DATE--> Since 1964, most "mainframe" computers (like IBM's S/360 and S/370 and S/390) and their operating systems (MFT, VS1, MVS, etc.) have been 32-bit. With 32-bit operating systems, you can access up to 2-4 GIG of RAM; in 1964 this was an unbelievable amount of memory... In 1964, A Meg of RAM filled a large room. Today, a few GIG of PC memory sticks from Staples would fit in a small purse. (Don't try this at home.)
(By the late '80s, 2 GIG was not enough for the mainframes.)
Anyway, dog Wolf says... When in doubt, go with 32-bit programs AND with a 32-bit operating system (though today (2006) it's hard to find application programs or operating systems that are NOT 32-bit... I guess this advice was more relevant back in 1995.)
And now... watch for 48 and 64-bit operating systems and programs, coming soon
to a PC near you.
AGENT
Usenet is the world's greatest source of information, bar
none. Usenet is filled with articles on every imaginable subject, available
to anyone on the Net... and you can post an article for zillions of other
folks to read... perhaps a question. (Think of Usenet as being like chat,
but for Netizens who are literate.)
To read and post articles from/to Usenet, you need a client program on your PC called a newsreader. Your newsreader client links across the Net to a news (Usenet) server. Thus, like most stuff on the Net, Usenet works in a "client-server" fashion... the client program runs on your PC, and the server program runs out there on the Net somewhere.
Many Web browsers (like Internet Explorer) also have a built in newsreader. These newsreaders do not have as many functions as a standalone newsreader programs. AOL also provides a built in newsreader (which has been the butt of jokes for several years).
One of the most popular newsreader client programs is Agent. Also available, with fewer features, is Free Agent... for free, what else? Dog Wolf recommends- Install the excellent Free Agent newsreader on your PC and check out Usenet. If you really get into reading and posting articles, then upgrade to Agent by paying a few dollars. Only then will you truly appreciate the additional features.
BACK TO THE FUTURE--> Today (2006), using the popular Google website, you
can read virtually every Usenet article posted within the LAST TEN YEARS; and you
can post replies to Usenet articles (written within the last month); or, you can
post new articles. Google-posting requires a brief registration process; it's not
quite as sophisticated as Agent, but it's close... and it's free... and you don't
need a newsreader client to enjoy Usenet... and you have ten years of unbelievable
articles in countless newsgroups to peruse. (Today (2006),You are very lucky today
if your ISP saves 2-4 weeks of articles.) Your dog Wolf highly recommends the
Google Groups.
ANONYMOUS FTP
In the beginning (before 1996-97 or so), the Net was a friendlier place.
Folks loaded up their FTP servers with every file imaginable and invited
the rest of the Net to download these treasures using an FTP client like
WS_FTP; a unique userid and password was not even required.
And so, from an anonymous FTP server out there on the Net, you could (and still can) download files of every type to your PC ... programs, MP3s, JPGs, you name it... without even having an account on the FTP server. You just log on using a USERID of ANONYMOUS, and you enter your e-mail address as the password (as a courtesy).
Some anonymous FTP servers will also allow you to "donate" files to other Netizens, allowing you to upload files from your PC to the FTP server. (But in 2006, some frisky hackers use this capability to install "interesting" daemon programs on willing UNIX computers about the world.)
Dog Wolf says... Anonymous FTP is among the world's greatest treasure chests, just waiting to be plundered. There are more free programs and pictures and music files and whatever out there on the Net than you can check out in a thousand and one nights.
Data downloads faster via FTP than it does from the Web. FTP establishes
two data "pipes" when you log onto an FTP server, and these pipes are connected
for the entire duration of your download... one pipe for data, the other for
commands. Data coming from a Web server, however, bounces about the Net like
balls on a pinball machine until it finally reaches you; there are no dedicated
pipes. (Thus the Web is called "connectionless," no connection is established
to a Web server; but TWO connections are established to an FTP server.)
AOL
(America Online) The largest BBS (and arguably the largest
ISP). AOL uses a Windows or Mac-based client-server format.
You install AOL's client software on your PC (from a CD or from their Web site or from AOL itself), and then you link to AOL's servers through your modem. (You also can connect to AOL through your ISP via the Net; if you do this, you'll avoid the busies that have become AOL's signature in many minds, and you'll also save $$$... $14.95/mo vs. $23.90/mo) AOL's CDs are free, and they're everywhere; they recently were taped to the bags of dogfood at the Giant SuperMart.
While AOL dominated the dial-up modem market until recently (slightly less than 1 out of 3 dial-up ISP accounts in the US are with AOL), AOL now (2003) seems to be having difficulty making the transition to broadband (cable, DSL, or satellite... all much faster than a dial-up modem); only 1 out of 30 US broadband customers were connected to the Internet through AOL as of early 2003.
In late 2002, AOL began losing membership for the first time; and it posted a 4th quarter loss of almost $45 billion (announced January 2003). During 2003, things only worsened for AOL; the service lost two million subscribers, leaving it with 24.7 million users by the end of 2003.
AOL is very easy for the newbie to install and fairly easy to configure, and it features an "all in one" approach to the Net. Dog Wolf Suggests--> Try it... only then will you truly appreciate the superiority of individual client software programs like Netscape, Outlook Express, etc. connected to the Net via an ISP (dial-up or broadband).
AOL also features copious parental controls, which some maintain are
aimed at adults who let their kids play unsupervised on the PC and the Net.
ASCII
ASCII is a code using integers from 0 to 127. Each of the
128 numbers in the ASCII code stands for a letter, a number, a punctuation
character, etc. And since any number from 0-127 can be represented by
just 7 bits, any ASCII character can be represented by just 7 bits. PCs often
store and send plain text using the ASCII code; E-mail and Usenet send and
receive ASCII 7-bit text. Programs and pictures and music, on the other hand,
use an 8-bit binary code, and they are not sent or received as ASCII characters.
(IMPRESS YOUR AARDVARK--> ASCII = American Standard Code for Information
Interchange).
ATM
No... these are not bank machines... though if you build an ATM network,
you may need to make multiple visits to your ATM machine to finance it. ATM
stands for Asynchronous Transfer Mode, and it's been around now (2006)
for 15 years. It evolved because of a desire by telephone companies both in the
US and in Europe to send voice, video, and data over their networks... and
over the SAME networks. ATM can thus carry voice, ordinary data, fax, real-time
video, CD-quality audio, imaging, and BIG (multi-megabit) data transmission.
ATM is a STANDARD (a "protocol") for sending and receiving data, both on LANs (over a small area, like an office building) and on WANs (over wide areas, like the whole ATT US network). ATM is a protocol "by committee;" many of its standards were compromises (like the 48-byte "payload" in each ATM cell... the US telcos wanted 64 bytes and the European phone companies wanted 32 bytes; (64+32)/2 = 48). (A byte is 8 bits grouped together, usually representing something, like a character or a program instruction code.)
ATM can transmit stuff (in theory) at 1.2 billion bits per second (bps), though ATM usually runs at 155 million bps to 622 million bps (the speed of many fiber-optic networks)... but 622 million bps is FAR from shabby... at 622 million bps, an ATM network could transmit the entire Encyclopedia Britannica (1997 printed edition, including graphics) in ONE SECOND. Yeah... Whew. (Many computers have trouble keeping up with this speed.)
ATM sends all data types as 53-byte "cells"... the 48 byte payload and a 5 byte address header. Thus if you dump a 1,000 byte TCP/IP packet into an ATT or Sprint ATM wide-area network, the 1,000 byte packet will first be chopped into 21 data frames, and each frame will be placed in one ATM cell.
Because ATM cells are 1.) small, and 2.) all the same size, ATM can move things along MUCH faster than if the frames were of variable sizes... network routers and other equipment can move fixed size frames MUCH more quickly... AND because all the cells are tiny (53 bytes), no one type of data can monopolize an ATM network... a tiny voice packet cannot get stuck behind a big old lumbering data packet. (Can you now begin to sense the influence of the phone comanies in ATM's design?)
Unlike TCP/IP, where data packets bounce around like balls in a pinball machine, and different packets during a single transmission often take many different routes, ATM fixes the route between the sender and receiver BEFORE the data transfer begins... it establishes, at the start, a circuit, a "virtual channel connection" (VCC)... another reason for its speed.
ATM supports QoS (quality of service)... a guarantee that your data will get through no matter how busy the network may be... if you're important enough. (It pays to be important, and you'll pay for ATM to think you're important.) Before ATM sends anything, it negotiates the speed of the path it'll be using... it decides in advance if your stuff will travel over I-95 (when traffic is very light) or the old US Route #1 (at rush hour).
ATM has grown slowly over the last 15 years becuase 1.) it requires
exceptional bandwidth to reach its full potential, 2.) it requires
specialized ATM hardware throughout its entire network, hardware made by a
relatively small number of vendors, and 3.) installing and maintaining an
ATM network (LAN or WAN) requires folks with mucho ATM experience... it's
not trivial.
BACKBONE
The Net is like a lot of cars running along highways. On the Net, the
cars are data packets. And each car sports a large sign saying where it
would like to to end up (like "Key West or bust") and where it came from.
Let's call our longest, fastest, and widest highways "Interstates" (since that's what most folks call them). And we'll have our Interstates cross each other or terminate at wide, high-speed "Beltways."
So, we arrive in Houston on I-10; we drive around the Beltway (I-610) until we come to I-45; and then we leave Houston on I-45.
The Net's highways are especially cool, because our circular Beltways have friendly traffic cops stationed about them. We don't even need to know which road to take out of Houston.
The friendly cops read those signs on our cars ("Key West or bust"), and when we come to the correct highway to take us toward Key West, they wave us onto it. Cool, yes? Yes.
On the Net, our Interstates are called National Backbones. The
beltways are called NAPs... Network Access Points. And the friendly
traffic cops are called Routers. (Not to be confused with these massive
routers are the small inexpensive routers that folks use to protect their
privacy at home when they go with a cable ISP... D-Link, Linksys, Netgear, and
SMC are some popular brands that require few repairs.)
BACK END
The back end of an ISP is the telephone cable(s) and associated hardware
that connect the ISP to the Internet. An ISP can have an excellent "front end"
(with plenty of fast modems, so you never get a busy when your modem dials
the ISP), but the ISP still may run like a slug in Hunt Valley in January
if its back end connection to the Net is overloaded.
(SMALL TIDBIT--> Small ISPs often don't connect directly to the Net.
They connect to bigger ISPs. Then the bigger ISPs connect to the Net.
See my excellent dog Wolf article How ISPs Work
for all the juicy details.)
BANDWIDTH
The bandwidth of a highway is how many cars you can get through it per hour.
The bandwidth of my bathtub is how fast the pipes in my house will let me
fill the tub with water. And the bandwidth of something on the Net is how
many bits of data you can get through it in a second.
The bandwidth of I-95 is perhaps 50,000 cars per hour. The bandwidth of a cable ISP is 36 million bits per second. (Slow tractor trailers, accidents, slow Ethernet cards, data errors, interference, etc, keep both highways and cable ISPs from realizing these maximum theoretical bandwidths.)
The term bandwidth is also used by folks on the Net to mean a vague, ephemeral thing that pervades cyberspace; the ether of the cyberverse. People will sometimes accuse you of wasting this vague bandwidth thing; as in, "You quoted the whole article and only added a one line comment? What a waste of bandwidth, you idiot." (Actually, you've wasted a little of the disk space at countless ISPs, not the Net's bandwidth.)
(NETIQUETTE--> When responding to an article on Usenet, don't quote
more of the original article than you need to; but do quote something,
so people will have an idea of what you're talking about. People who respond
to posts and quote nothing are often called "idiots." (The nitty gritty of the
Net has a culture and lifestyle all its own.)
BAUD
Even a lot of "gurus" are often confused by the difference
between baud and bits per second. So we'll start at the
start.
Binary things have (by definition) only two states. The Giant Supermart is either open or closed... two states. A regular light bulb is either on or off... two states. The Giant and the light bulb are binary things. Binary things are represented by a bits. And a bit can only have a value of 0 or 1... it's either off (0) or on (1).
Every character transmitted across the Net is represented by either 7 or 8 bits. And strings of characters are sent through modems and phone lines as strings of bits, like... 0110101011000.
Bits per second (bps) is the number of bits sent or received per second. Like, 56K modems send and receive 56,600 bits per second (in theory; in practice, good luck).
But BAUD is something different. BAUD is the number of times per second that the frequency or the voltage of a signal on a phone line (the sound or the tone on the phone line) changes.
If the frequency or the voltage of the electricity on a communications line changes 2400 times per second, we say the line is running at 2400 BAUD. And 2400 baud is about the maximum speed at which a plain old telephone line can carry changes of states.
BUT... and here's the rub... one baud... that is, one change of the electrical state of the phone line... can cleverly be made to represent MORE than just one bit. SO... maybe a 2400 BAUD modem, by using some secret code (like four different tones), can send FOUR BITS for every change of state on the phone line... four bits PER BAUD... four bits with every electrical state change. Then a 2400 BAUD phone line could carry data at 2400 x 4 = 9600 bits per second (bps).
Typically, a 9600 bps modem sends out four bits 2400 times per second (2400 baud). The voltage on the phone line (the sound) changes 2400 times per second. And that's what baud is all about. Simple, yes? Yes.
The only part that is confusing is that many folks incorrectly use BPS and
BAUD interchangeably.
BBS
Bulletin Board System. An electronic bulletin board on some remote computer.
Folks have discussions (just like Usenet), download files and pictures (like
FTP), make announcements, etc. There once were a zillion BBSs in the world,
and most were really just PCs with a few phone lines connected (one or two
customers at a time). Some well-known BBSs are dedicated to just one topic,
like home repairs. And many BBSs will even connect you to the Net. AOL is the
largest of the BBSs.
Today (2002) many BBS's have switched over to the Net; thus many former
Bulletin Board Systems are Web sites now... you no longer have to dial up
each BBS on your modem; you just connect to your ISP and "surf" the
Web.
BEETHOVEN'S STRING QUARTETS
Yes... chat ala AOL, E-mail, and The Web (tada) are the biggies today
(2002), but IRC (Internet Relay Chat) and Usenet (post an article or reply
to one) and anonymous FTP (download programs, pictures, music, movies) are
the true treasures of the Net.
IRC and Usenet and FTP are pure fun. Getting to love them may take a bit
of effort, but the same is true of Beethoven's string quartets, and think of
how much pleasure they give if one does make the effort.
BINARIES
Some parts of the Net, like E-mail and Usenet, were originally
designed to carry only text. These parts of the Net use 7-bit ASCII
codes to represent each text character.
Other parts of the Net (like FTP and the Web) can handle 8-bit binary codes just fine. These 8-bit binary codes represent the bytes of picture files, programs, sounds, etc.
BUT THEN... how do you attach a program or picture with 8-bit bytes to E-mail or to your Usenet post? Q.E.D. (Quite Easily Done.)
Your E-mail program and your newsreader (for Usenet) will convert the 8-bit binary code to a 7-bit ASCII text code, and then back again. These 7-bit characters representing 8-bit bytes are called "binaries" on Usenet. In fact, on Usenet, there are many newsgroups are dedicated to binaries, like alt.binaries.pictures and alt.binaries.collies.
CAUTION--> Do not post binaries to non-binary newsgroups; you
will be called an "idiot" (or even worse, a "Fluque-wit").
BINHEX
BinHex is a method, similar to UU-encoding, used to convert 8-bit binary
files like programs and pictures to 7-bit ASCII text files, so that you
can attach these files to 7-bit text e-mail letters. (BUT... today (2002),
most E-mail uses a code called MIME for its attachments. Whatever.)
BLERS
(Impress Your Analyst--->) Blers (Bit Link Error RateS) are
errors in data and blocks of data that have been received by your modem.
If there are more than two block errors (more than 2 blers) during several minutes of connection, your modem may be experiencing problems receiving data from your phone line.
Thus we often hear, "That $@#@!!! Courier modem had 231 blers in just 5 minutes!" (not cool). On the other hand, just one bler every 12 minutes is considered very cool by gamers playing Quake.
(If you give a USR modem the famous "ATI6" command, it will respond with
lots of cool statistics, including blers. Well, you asked.)
BROADBAND
Broadband is sending and receiving stuff to/from the Internet by CABLE or by
DSL or by SATELLITE or by WIRELESS or by HIGH SPEED PHONE LINES. The advantages
of broadband are 1.) it's much faster than a 56k dialup modem (Precise
Networking Solutions requires that data be transmitted at 256 kilobits per
second or faster to be considered broadband); 2.) you don't tie up a phone line
when you're online; and 3.) you don't dial up, your connection is always on.
Because of the higher speed of broadband, you can receive streaming-video and
live TV feeds.
By the end of this year (2003), over 22 million homes (21% of all households) and over 7 million businesses in the US will have high speed Broadband Internet access.
Your broadband modem communicates with your PC by Ethernet; you should connect your broadband modem to your PC through an INTERNAL ETHERNET CARD. (It's faster than a USB-Ethernet adapter... we've tried both.) And visit the NAVAS Web site after you're up and running with broadband to optimize your speed, especially if you're running Windows 98.
If you have more than one PC, you may want to share your connection to broadband (e.g., the output of your cable modem) across two or more PCs... in effect, set up a small network in your home or office. This is easily done by having an inexpensive router installed; the router controls the single static IP address that you received with your broadband connection. The router gives each of your PCs a secret, internal IP addresses... an IP address invisible to the outside world... invisible from the Net. The router "routes" all the packets coming in from the Net to the correct PC; and it merges the packets that are heading out onto the Net coming from all of your PCs.
Thus you can be browsing the Web from your bedroom PC, while your significant other browses the Web from the Den; and your ferret browses the Web using a laptop on your sofa... all simultaneously, all at high speed. The router routes the right packets to the correct PC. It seems to everyone as if they are the only one connected to the Net. And the laptop thing works because a router can include a transmitter and receiver... it can be both a wired and wireless router.
Almost all external mischief from "out there" on the Net that hits your
router goes "poof"... it fails instantly. This is why most folks who have only
one PC in their home or office still install routers. Routers are especially
important if your broadband connection to the Internet is via cable... because
you and all of your neighbors will be on the same local loop... a privacy
problem. Having a router installed is a must for anyone doing broadband through
a cable modem.
BROWSER
The client program that you run on your PC when you want to
retrieve and look at stuff out there on the Web is called a browser. Many
browsers, like Internet Explorer, can also send and receive E-mail, read
and post to Usenet newsgroups, download via FTP, and perform various other
tricks.
Put another way, a browser is a way to view the stuff on the Net,
including multimedia. And where do we find pictures and animation and sounds
on the Net? On the World Wide Web? Right. Hence the name, Web Browser.
BROWSER CACHE
Cache stores stuff close by us, so that we can get to it fast. A Web browser's
cache stores a page's HTML code, as well as any graphics and multimedia files
embedded in the page. Then, when you want to view a previous page, everything
doesn't have to be downloaded from a Web server out on the Net all over again.
Since accessing your hard disk is much faster than Net access, this
speeds things up.
Many ISPs also cache Web pages. Most time-sensitive pages on the Web... like stock quotes... use the "http expires header," so that after a certain amount of time has elapsed, your Browser will be forced to request a new page from the Web server.
BUT... an ISP with a proxy server (like AOL) may ignore such refresh requests, and just give you the same cached page again and again. (We say that it doesn't "punch through.")
Dog Wolf's Tip- Clear your browser's cache periodically. The main reason
that you want to clear your browser cache is for better performance...
especially on a slow or low-memory PC. Cleaning out the browser cache
(and the browser's history list) can dramatically improve the speed of
a browser. (Reducing the size of the cache and the history list can also
speed up your Web browser.)
BTW
Shorthand for "By The Way." Shorthand is used in E-mail and when chatting
and on Usenet to "save bandwidth." (Right.) In reality, shorthand is often
used by newbies in an attempt to demonstrate that they're not newbies
(newcomers to the Net). And shorthands do save you time when you're typing.
CAT-5
When you connect computers together over a small area (like in an office building,
or in a home office) so that they can exchange data, we call that a Local
Area Network, or LAN. The wires and hardware (e.g., coupling, junctions, etc)
are called the CABLING.
The cabling is a critical factor in how fast a PC can send and receive data from a LAN. Precise Networking Solutions recommends Category-5 for the cabling connecting each PC to the LAN... to the actual wires that connect each PC together. In general, the more Cat-5 cabling the better, on an Ethernet network.
Cat5 cabling consists of four twisted copper pairs, and it is pre-tested to assure operation at 100 MHz (100 Million bits/sec); if the routers and Ethernet cards are sufficiently fast, Cat5 cabling can support one GHz (one billion bits per second Ethernet, or gigabit Ethernet). The Cat5 cable can be shielded on the outside to reduce interference; shielding does not allow data to move any faster in CAT-5 cabling, but it does reduce interference and thus it reduces data errors.
Cat3 looks similar to Cat5, but Cat5 has been tested at 100 MHz and passed. Cat-1 is simply twisted pair used on a phone line; it cannot pass data even at one million bps. The gist here... when wiring a LAN, know what cabling to use, whether it needs to be shielded (perhaps it runs next to a noisy transformer)... know what hardware constitutes a Cat5 cabling, etc. And match the cabling to your routers
MORAL--> Know what you're doing, use the proper wire, hardware, routers, shielding
or not, and so on; almost anyone can put together an Ethernet LAN... but how it works
when there is interference, the actual maximum consistent data speed depends on a
lot of inter-related factors. The LAN is even more complex when it includes
wireless routers. Let the gurus wire your LAN; then it works just fine 24 hours
a day.
CGI
Usually, when you give your Web browser a URL
(like... http://www.learn.com/~internet/ethernet.html), your browser
contacts a Web server out there on the Net named www.learn.com,
and that Web server scans its hard drive directory internet and returns
to you a file called ethernet.html.
HOWEVER... a Web server can also be set up so that when files in certain directories are requested, instead of the file being sent back to you, the file is instead executed on the server. So, for example, when you give your browser a URL like... www.learn.com/isp-cgi/networks.html, file networks.html in directory isp-cgi is executed on host www.learn.com as a program, and the output of that program (whatever it may be) is then sent back to your browser for display.
This capability to execute programs on a Web server and send back the
output is called Common Gateway Interface or CGI; and the programs
stored in the special CGI directory at the Web server are called CGI
Scripts.
CHANNEL
A channel on IRC is like a chat room on AOL. Each IRC
channel usually focuses on a specific topic, or is desgned to appeal
to certain folks (e.g., Aussies). BUT... on IRC, you can be on up to
four channels at one time.
If a channel name starts with a #, then that channel exists on all
IRC networks (for instance- #chatzone), but the #chatzone's on each IRC
network are completely unrelated to each other, and they are not (normally)
connected in any way with each other. IRC is a wondrous and mysterious
thing to explore.
CHATTING
Talking to other folks on the Net by typing and
reading their typed responses on your monitor in real time is called
chatting.
You now can also chat by having actual voice conversations and/or
seeing other folks on the Net via video. (These are surely exciting times
in which to live.)
CHIP
PCs contain various types of "chips." Here, we'll look at the PROCESSOR CHIP.
And in the next definition, we'll take a peek at the ever mysterious CHIPSET.
So what's this chip thing all about?
Well... The part of a computer that actually does the computing is made from "switches."
A computer switch works just like my refrigerator door; sometimes it's open, sometimes it's closed. When it's open, I can binge; when it's closed, I have to make do with Cheez-Its. (You know the drill here.)
Now... I have two neighbors, George and Saddam (no, not their real names). Imagine that, after a massive Merlot drinking contest, we all decide to wire our three refrigerator doors together... so that my fridge only OPENS when George and Saddam's fridge doors both are CLOSED. Why? Who knows, it was good Merlot. So?
So, what we have built with our refrigerator doors is what engineers like to call a GATE. Dawn is open only when 1.) George is closed AND, 2.) Saddam is closed. That's a gate.
Ok... In the part of the computer that does the ACTUAL COMPUTING, we have similar gates, called LOGIC GATES. A gate in a computer might allow current to pass through my transistor only when there is no current coming from neighboring transistors A and B. Right... So?
So this. With logic gates like this, and other gates of various simple sorts similar to these, you can compute anything in the world that can be computed.
(No, you can't compute the last digit of PI... that can't be computed, PI goes on forever (we think)... but you CAN compute my Federal and State taxes (Oy! And if only you could pay them while you're in the neighborhood).)
BUT... Anything that can be computed CAN be computed using just a few simple gates. (Trust me on this one... or peruse Marvin Minsky's classics on computation.)
Early computers ('40s and '50s) built their gates out of relays and vacuum tubes... big, hot, frequently burned-out, slow vacuum tubes. By the '60s, computer gates were built from transistors... smaller, cooler, longer-lasting... and FASTER.
As the years passed, transistors grew smaller and smaller; very, very small. By the '90s, millions of transistors could fit on a chip of material the size of my unbroken fingernail... and in fact the transistors (and a few other components) WERE actually placed on a CHIP from a silicon crystal... hence the name "CHIP."
The zillions of transistors forming gates on a chip of silicon... gates that do our PC's actual computing... form THE PROCESSOR CHIP. (Tada.)
And just add a few trimmings around the processor chip and stick it in a little case perhaps 1-2" square and about 1/2" thick and you have a Pentium chip or some such. Simple stuff... just millions of gates (not to be confused with Gates' millions) opening and closing on a chip... opening and closing to do your computer processing... your PC's PROCESSOR CHIP.
Of course (why of course?) there are OTHER chips on your computer besides
the ones with the gates that actually compute. Read on, mate...
CHIPSET
Just like routers control the flow of data on a NETWORK, the CHIPSET controls
the flow of data in your PC.
The chipset is a couple of chips inside your PC. These chips, like the processor chip (e.g., Pentium, etc), also have a zillion transistors (and even a lot of gates), but they don't compute taxes (thank Goodness). The chipset is NOT to blame for the HUGE sum of money that TurboTax says I owe to Uncle Sam (and Uncle Maryland).
No... The chipset is (are?) your PC's friendly traffic cop chips, NOT your PC's computing chip.
The chipset traffic cops control the flow of data to and from THE PROCESSOR CHIP, and to and from memory (RAM), and pretty much to and from everywhere else in your PC.
In the spring of PCs, there were MANY traffic cop chips (lots of transistors sitting on chips of silicon crystal)... like one chip for the modem and this little chip for the monitor and this little chip went to market...
As things in PCs became cooler (smaller, faster, cheaper), all these diverse traffic cop chips were gradually collected together into (usually) two little chips called the CHIPSET... two chips that control which bytes go where in your PC.
Chipsets DO actually exist; after I asked, the folks at Precise Networking
Solutions opened up a PC and showed me a chipset... it looks like two tiny
black boxes, each about 1" by 1" (each like half the size of the Pentium
chip)... the Pentium processor chip (or Celeron processor chip or whatever)
being the guy who does the actual computing.
CLIENT-SERVER
If I connect to a host computer somewhere out on the Net
that is running an FTP server program, and I want to download
some files from him to my PC, I need to be running a program on my PC
called an FTP client.
FTP server program on the host computer out there, FTP client program on my PC.
Voila, stuff downloads to my PC. That's an example of a client-server.
Another example... if I connect to AOL in Virginia (the "AOL server") using my modem, and if I'm running AOL's client program on my PC, then I can chat in AOL's chat rooms. (Whoop.)
If I have mIRC running on my PC (an IRC client), and I connect to an IRC server out there on the Net, then I can do some real, manly, robust IRC chat.
The client progam on our PCs gets stuff from (or sends stuff to) a server program running on a host computer out there on the Net, maybe 10,000 miles away from us. Each server program (like a POP3 server from which we download our E-mail) needs a specific kind of client program (like Eudora) to work. Almost everything on the Net that's fun to do is client-server... that is, it requires a server program out there somewhere on the Net and an associated client program on our PCs.
And that is the secret of the Internet... installing some client program
on our PCs and then connecting to a related server program out there on the
Net... Newsreader on our PC, connect to news server out there on the Net...
Voila, we can do Usenet. And on and on and on... the Web, whatever,
you name it... chess client on my PC, connect to a chess playing server
"out there"... I can play chess.
COMPUTER NAME
If a host is named learn.networks.net, then learn
is called the computer name... it's the name of one of the computers
at some site out there on the Net. isp.networks.net is the name
of another computer at the very same site.
Names on the Net are structured like learn.networks.glossary.hopkins.edu. The last two labels on the right are the name of the "little network" where the computer we want to reach lives. (Our desired computer lives at hopkins.edu in this example.)
And the label(s) to the left of these last two are the name of the specific
computer on the little network that we want to reach...
learn.networks.glossary in this example. And this is the computer name.
COOKIE
If you're surfing the Web, going from site to site, then some
Web sites may write a tiny text file on your hard drive called a cookie. Most
browsers give you the option of blocking these cookies, or they will warn you
before the tiny cookie file is written. Sites that write cookies usually do so
only the first time that you visit them. The cookie that they write usually
contains a code number that they read from your hard drive on your subsequent
visits to the site... so that they can uniquely identify you.
Cookies can be beneficial... a Web site may use your tracking number that it writes in your cookie to keep track of your preferences... or perhaps to remember the particular stocks that you're interested in. But cookies can also allow a site to track everything that you do while visiting their site. A site that sells stuff could use a cookie to track merchandise that you looked at but didn't buy. Or, a news site might track whether you read a story about John McCain or Jennifer Lopez.
And if you've given a site your real name or address, the site can begin building a detailed file on your habits.
If you're curious about your cookies and you're running Netscape, look in C:\Program Files\ Netscape\ Users\ Your_Name\ cookies.txt. If you're running Internet Explorer, look in C:\Windows\Cookies. On the left side of each line, you can see the name of the site that wrote the cookie.
One way that cookies can become intrusive is by using clear GIFs. A clear GIF is a tiny picture that you don't see that can be embedded by an advertiser in a page that he returns to you. Even though you don't see the clear GIF, its presence allows the advertiser to write a cookie to your PC. Some Web sites feed you a clear GIF to prove to their advertisers that their hit statistics are valid.
This Web site feeds you NO cookies... bad for you, except to
save your password and preferences, in our dog Wolf's opinion. And so, while
you can't eat these Web cookies, you can surely purge them off of
your hard drive.
CYBERSPACE
Cyberspace is everything in the known (and unknown) universe
that folks can access via some computer network. It's the cyber universe
(or cyberverse). It's the mystical, magical world you enter when you log
onto the Net... as opposed to old-fashioned, boring non-cyberspace Reality,
where you have to work for money, and you have to pay taxes, and where bills
come in the mail, and where you get shy when you have to meet real people,
and where everyone is not brilliant and beautiful and imposingly endowed.
In cyberspace, even a dog like your dog Wolf can create a Web page like
this one. And in cyberspace, at 430 AM on Sundays, all cats are gray,
and all ISPs are equal.
And cyberspace is independent of physical geography.
DAEMON
Unix machines have lots of programs called daemons
(pronounced dee' - menz) running endlessly in the background. A
daemon usually spends most of its time sleeping. Daemons either wake up
periodically and search for tasks to perform, or they wake up when some
event takes place.
For example, the cron daemon wakes up periodically and performs all of the tasks specified in a particular Unix directory. And many computers running the Unix operating system run a print daemon, which wakes up and prints whatever is in the print queue whenever a program writes something there.
Most Net functions, like serving up Web pages or FTP or E-mailing,
are performed by daemons running on a Unix computer out there on the Net
somewhere. Daemons are also popular with some hackers; daemons can be placed
on some willing server, and they sleep undetected in the background until
awakened by the hacker to perform some function... such as denying folks
access to some popular Web site. Not very impressive... breaking is always
easier than building. (See second law of thermodynamics.)
DEDICATED PHONE LINE
This is something you can get from many ISPs. It can be a leased phone line
(where you're connected without dialing), or it can be a phone number that
only you have.
The line will never be busy, and you can use it to stay connected to your ISP forever and ever; which is cool, if you're running your own server. The rub is that dedicated lines usally cost hundreds of dollars per month.
But... with a dedicated line connected to a real ISP, your PC can
have a direct, permanent connection to the Net. Dedicated lines may be
expensive, but they're also very cool. (Cable connections work just like
dedicated phone lines, though most cable companies frown upon you running
your own server.)
DHCP
DHCP stands for "Dynamic Host Configuration Protocol." DHCP is a way that
your PC can get a unique, working IP address when you dial into your ISP
(some heavy alphabet soup here).
Why? Well, you need an IP address in order to be able to direct good stuff from out on the Internet to your PC, like the Web pages your browser requests. (It's like your telephone number... you usually need one to be able to receive calls.)
DHCP is a better way for an ISP to assign you an IP address than just picking one out of the air and then seeing if anyone else is already using it. Well, you asked.
Also, the knowledgeable folks at Precise Networking Solutions in Baltimore,
Md (aka "The Boss") tell me that DHCP is a cool way to assign IP addresses
to all the PCs in your home or business if they're connected to the Net via
a router. And, they remind me, if you have a cable modem in your home, you'd
best also have a router between that modem and your PC or PCs to protect your
privacy; i.e., to keep the computer nerd down the road out of your hard drive.
DIAL-UP NETWORKING (DUN)
Dial-Up Networking, included with Windows, allows your computer,
connected to a network through a modem, to communicate with other computers on
the network just as if your computer were a part of the network
(only more slowly).
Using DUN, you can get your E-mail from your network at work, you can send a file to your printer at work, you can run programs on your computer at work... all from home.
DUN allows you to connect to one or to many different ISPs, using different
USERIDs and/or different modems if you like, just by clicking on the proper
icon. And DUN takes care of the winsock and the TCP/IP and the dialing and all
of that stuff. If you have DUN, flaunt it... it's the greatest idea since
female intuition.
DIGITAL
Pay attention to this one, because many folks (including some comp sci
professors) muck it up (threw in an Aussie-ism there). Ok... If something
is digital, it has discrete states. Whoop. So what does that mean?
The pole lamp in my bedroom has three bulbs. It has FOUR states... all bulbs off, bulb #1 on, bulbs #2 and #3 on, and all three bulbs on... dark, romantic, brighter, and very bright. My pole lamp has four discrete states. Things which have a finite number of states are called DIGITAL. My pole lamp is digital; it only has four states, and four is a finite number.
The Giant FoodMart is either open or closed; it has two discrete states (it's digital). And it's also BINARY. Why? One more example first.
The light in the bathroom off of my bedroom has two states; it's on or it's off. It is DIGITAL (two discrete states). And it's also BINARY. Why? Digital things with only two discrete states are called binary.
LOVE is binary (he loves me, he loves me not... ). The circuits in PCs are almost entirely binary... their voltages are always in one of two states, ON or OFF. Why are PCs designed to be (digital and) binary?... because binary technology is very, very cheap. It's the $$$. Most (but not all) computers are digital and binary.
Returning to my bedroom, I have a reading lamp with a dimmer. It has MANY states. How many, you ask me? MANY. In fact, in theory, it has an endless number of states, an INFINITE number of states. Things which have an infinite number of states are called ANALOG. My weight is analog. (I'm not saying here that MY WEIGHT is infinite, just that it can be in an infinite number of states... 107.00, 107.10, 107.15, etc.)
But, when I get on my digital scale however, the scale displays some "digits" from 0 to 300. The display on the scale can be in one of 301 discrete states; thus, the scale is digital (but not binary). This scale is an example of an analog to digital converter... it converts my analog weight to a digital display. Special purpose computers (often used for simulations and for solving differential equations) have ANALOG circuits. Programming analog computers by rewiring their front panels can be very theraputic.
In late 2004, we are seeing almost everything in the entertainment aisle switching to DIGITAL. (PCs always were digital, primarily because you can make very fast digital chips for computers very VERY cheaply.) Now... digital cameras, camcorders, TVs, and video recorders deliver sharper, clearer, cleaner pictures with more details than their older analog counterparts. And with digital equipment, the functionality is nothing short of unbelievable. For example, with digital cameras, you can preview your photos, delete the bad ones, crop out the tour guide in front of the Grand Canyon, etc.
THE FUTURE--> Your PCs are digital, your digital cameras (etc) are digital.
Watch what happens when the entertainment devices and your PCs are smoothly
integrated by 2006... like you could take your camera to a restaurant near Niagra
Falls... a restaurant with a "hot spot"... and VOILA, all of your pictures are
magically uploaded to a space on the Net; your friends and family can see all
your vacation photos (should they desire) just a few minutes after you've snapped
them... and now your photos have departed from your camera and are safely tucked
away out on the Net... so you can start shooting pictures again on the same memory
card. And that's just the beginning.
DNS
MEMORIZE THIS TO IMPRESS EVERYONE-->
Ok, let's assume that you want to browse www.dogwolf.edu.
Well... you can't. Because www.dogwolf.edu is a DOMAIN NAME,
and IP (the part of TCP/IP that actually moves stuff around the Net)
can only work with IP ADDRESSES.
SO you can't get a Web page from www.dogwolf.edu (an easy-to-remember domain name) until it gets translated into an impossible to remember "IP Address," like 216.163.77.8.
So... who translates these DOMAIN NAMES into IP ADDRESSES? TADA... DNS to the rescue. (DNS = Domain Name System.) How does DNS translate a domain name into an IP address? (This is the kind of stuff that will make your SO think of marriage for sure; or you may just scare him or her with the power of your mind.)
When an ISP or an organization (like precisenetworking.com) wants to connect to the Internet, it has to register with some organization... like InterNIC. And as part of this registration process, the organization has to list at least TWO "DNS Servers;" these DNS servers must return an IP address for every domain name in the organization. And it's the organization's job to keep the data on its DNS servers current. Hold this thought.
Every TCP/IP product contains a special program called "The Resolver." (Great movie title.) When you want to browse or FTP or telnet or whatever, you specify the domain name you want to go out to, and the resolver converts that domain name to an IP address.
You want to browse www.dogwolf.edu? The resolver program in TCP/IP on your PC converts that domain name to 207.65.74.114. How does it perform this modern miracle, you ask your dog Wolf? Stay tuned.
STEP ONE. The resolver looks in YOUR local DNS server. If you're on an ISP, it looks in the ISP's DNS server. And if the domain name that you want converted belongs to your local domain... that is, if it's on YOUR DNS server, the resolver reads the record for it, retrieves the IP address, we're done. Not very exciting.
STEP TWO. Pay attention here, because this is important. When the resolver asks your local DNS server for an IP address, and the domain name is not on your local server, then your DNS server goes "out there" onto the Net for help. (We'll tell you how in a minute.) When it gets the IP address from "out there," it not only gives it to you, but it also stores the name and address on a local hard drive, called a cache. In STEP TWO, the resolver checks its local cache to see if the name and address are stored in there. If it finds a match, we're in business, we're done.
BUT NOT ALWAYS. Ever try to reach a bunch of Web sites and find some of them giving you "Resolving host www.aardvark.edu" and never getting any further; then in a few hours all is well again? Think your ISP's local DNS cache may be having problems? Uh Huh. But assume that STEP TWO here goes Ok, and the resolver just doesn't find a match in the local cache. To review and preview the whole process-->
NEED IP---------RESOLVER---------DOMAIN NAME
ADDRESS PROGRAM ON LOCAL DNS--------Get it.
SERVER? yes
|
|no
|
GO TO A ROOT SERVER-------------DOMAIN NAME
"OUT THERE." GET ADDRESS no IN LOCAL DNS---------Get it.
OF DNS SERVER FOR DESIRED CACHE? yes
DOMAIN
|
|
GO TO THIS REMOTE DNS
SERVER. GET IP ADDRESS.
RETURN IT TO RESOLVER
PROGRAM. ALSO CACHE IT
ON LOCAL DNS SERVER.
STEP THREE. We're still trying to resolve www.dogwolf.edu. Our local DNS server now sends the dogwolf portion of the name to the .EDU Root Server "out there" on the Net somewhere. The .EDU root server knows about dogwolf.edu (and every other domain name ending in .EDU).
(There are actually multiple identical root servers "out there" on the Net for .EDU and for .COM and for .ORG and so on... for every domain.)
The .EDU Root Server has information in its tables that tell it the address of dogwolf.edu's DNS server. It sends that address to OUR DNS server. OUR DNS SERVER then queries the dogwolf.edu REMOTE DNS SERVER, and it gets the IP address of www.dogwolf.edu. And now you can rock 'n' roll and start actually browsing www.dogwolf.edu.
As we said, your local DNS server (the one at YOUR ISP, or at your organization) also caches this IP address on a disk drive, so the lookup process usually goes pretty fast. The next time your ISP sees www.dogwolf.edu, it ALREADY has the IP address, it "remembers" it from the DNS query that it did the first time.
The long process described above with the DNS root server only happens when your ISP has never been asked about a certain remote domain name before (or if a locally cached entry has expired).
(IMPRESS JOHN NASH--> How, pray tell, does your local DNS server know how long to keep an entry in its cache? A deep secret--> when the remote DNS server sent the entry with the IP address, recall? Well, it also included in its entry the MAXIMUM TIME that the entry can be cached (one day is a common value). Of course, the organization running the DNS server may de-cache the entry earlier than recommended, perhaps because cache is running out of disk space, or because there are too many entires in its cache and things are running slowly, OR... the ISP/ Organization may be getting angry calls and realize that its cache is mucked up. (Aussie term, sorry.) ...is it common to worry about unmatched parentheses in prose?)
Yeah, there ARE a few steps to it. But it's not rocket science. (More like meeting a beautiful woman and chatting with her and courting her and... and...) And this DNS system, where there is actually a "distributed database," almost always works... millions of times each hour. And it's pretty much transparent. And this is how the DNS (Domain Name System) REALLY does its thing, no hooey.
And you're now among the 0.05% of Netizens who know and understand this.
And once YOU know that Aunt Biddie's phone number is 410-936-1212... uh, sorry... that www.dogwolf.edu's IP address is 216.163.77.8, you're free to bypass the whole DNS lookup process and simply give your browser http://216.163.77.8, which will work just fine, and may even save you a second or two.
(Ok... it will USUALLY work fine... there are some "party lines" on the Net. Just like sometimes folks in different houses will share the same phone number, sometimes a few Web sites on the Net will share the same IP address... and you cannot get the Web page you want just by sending the correct IP address... you also have to send the host name. Sharing IP addresses is a type of Web virtual hosting.)
If you're running certain versions of Windows, you can go to the DOS
(command) window, give it the line command "NSLOOKUP WHATEVER" where
"WHATEVER" is some domain name, and watch it return an IP address for
you from your local DNS server.
DOMAIN
Names on the Net are made from labels separated by dots. The labels
themselves are arranged in a tree-like structure... a naming tree.
If a host name (the name of a specific computer on the Net) is dog.wolf.net, then (a very small part of) the naming tree would look like...
Tree Structure
---------------------
|
NET
|
--------------------
|
WOLF
|
----------------------
|
DOG
...and the DOMAIN NAME for the label dog would be dog.wolf.net... we CLIMB the tree to get DOMAIN NAMES.
The DOMAIN NAME for wolf would be wolf.net.
And the DOMAIN NAME for net would be net.
To identify DOMAINS, we go DOWN the tree. Our tree above shows the DOMAINS net, wolf.net, and dog.wolf.net.
We call the the highest level domain, in this case net, THE TOP-LEVEL DOMAIN.
We call the two rightmost labels THE SECOND-LEVEL DOMAIN. Here, that would be wolf.net. This is the SITE or "little network" (or LAN) name.
We call the second label from the right the OWNER; here, wolf owns this specific computer.
Everything to the left of two rightmost labels constitutes the name of the specific computer; here, it is dog.
For an in-depth explanation of naming on the Net, with copious
examples, see my excellent dog Wolf article How
The Net *REALLY* Works.
DOWNLOAD
If you copy something (a picture, a program, a song,
whatever) from some computer "out there" on the Net to a disk on your
PC, you've downloaded it. When your browser requested this page from a
Web server out on the Net somewhere, and you got a copy of it to display
on your monitor, you downloaded it.
For example, E-mail programs like Eudora will download your accumulated E-mail from your ISP's (POP) mail server down to your PC.
And UPLOAD is just the reverse... when you copy a file from your PC's disk to a computer (server) "out there" on the Net, you've done an upload. If you have your own Web site, you'll be uploading files from your PC to some Web server "out there" on the Net.
WS_FTP32 is a popular program that uploads and downloads files between
your PC and some computer out on the Net.
DSL
DSL stands for Digital Subscriber Line (Technology).
It's also called xDSL, and ADSL is a common variant.
DSL runs over POTS (plain old telephone service) lines. (Lotta alphabet
soup going on.)
Like cable, DSL is a faster way to access the Net than a 56k dial-up modem. And like cable and satellite, DSL is a form of BROADBAND. (Cable (11%), DSL (4%), and satellite (1%) are the three primary forms of broadband... that is, they allow accessing the Net faster than you can with a 56k dial-up modem. The percentages are the percent of home Internet subscribers using that technology in March 2003.
With DSL, your Net packets travel over your old regular copper telephone lines along with your voice; a "splitter" separates your voice from Internet data. (In fact, DSL cannot travel over fiber-optic phone lines, and it often has problems with the newer "thin" copper wires... it's a technology conceived in 1988 that works best on the old copper phone lines... as long as they are in good condition.
A negative of DSL is that the lines from your computer to the local phone company are not always DSL ready; sometimes, a whole lot of fiddling is required. And your DSL Internet provider may NOT be your local phone company = finger-pointing. And you generally must be within three miles of your local phone comapny for DSL to work... three "copper wire" miles, not three "crow flying" miles.
DSL can carry data at speeds up to 6 million bits per second (vs 56,600 bits per second at best with your v.90 dial-up modem). Often, folks can download using DSL at 1.5 million bits per second; and (using ADSL) you can upload (send stuff to your ISP) at 128,000 bits per second.
DSL is superior to cable in some ways, in your dog Wolf's opinion... you're not sharing "the line" with everyone else in your neighborhood, so DSL is more secure. (You still should have a router between your DSL modem and your PC.)
And the download speed doesn't drop off as more and more of your neighbors begin watching Victoria's Secret via RealVideo, as happens with cable... many cable networks are like apartment buildings... there's not a lot of hot water when everyone takes a shower at once.
However, DSL is finicky; it needs to be installed carefully... if you've done some rewiring of your home phones to add extensions, etc, all that rewiring may need to be redone; and there can be interference if two copper wires carrying DSL data are in close proximity in bundles of wires (a problem commonly called cross-talk.). And as we mentioned, DSL can only work if there is less than three miles of copper wire between your PC and the local phone company's central office. (We already mentioned the fiber-optic problem.) And if your phone line runs through one of those boxes that permits multiple conversations using a single pair of wires... forget DSL. Don't sign anything in stone until you first try DSL from your home or office.
When your DSL line reaches the local phone company central office, the data is "split off" from any voice conversation on the line... yes, with DSL you can talk on your phone line and use it to carry data at the same time (though you may hear a clicking sound when you use your DSL line for talking while doing a data transfer); and then, your phone company sends the data portion to your ISP. So, with DSL, you have more flexibility in chossing an ISP than you do with cable.
With DSL, you're always connected to your ISP... there is no dial tone for the Internet. This makes it a bit harder to change ISPs; and obviously, since you never disconnect from the Net, your IP address will never change (static IP address) with a DSL connection to your ISP... a potential security problem here... hence the need for a broadband router.
HINT--> Most DSL will connect to your PC using the PPPoE (Point-To-Point Over Ethernet Protocol). The overhead for this protocol is usually handled by software, like the client Windows XP provides. BUT... you can increase speed and stability by letting your ROUTER do the PPPoE processing. (You need the router anyway between your DSL modem and your PC for security reasons.)
CONCLUSION--> In Maryland, Comcast cable downloads three times as fast
(3 Mbits/ sec) as does Verizon DSL. But DSL is still plenty fast; if you convert
from a 56K dialup modem to DSL, the speed of DSL will shock you for the first few days.
And remember that DSL is private, while cable is shared with all of your neighbors.
E-mail is by far the most popular Internet activity (2006).
E-mail allows you to use your PC to send letters and files
across the Net to specific folks (or groups of folks) at other computers
that are also connected to the Net. (If you send huge quantities of big
letters containing unsolicited garbage, that's called mail-bombing.
Sending small to moderate quantities of unsolicited garbage is called
spamming. Folks who do mail-bombing are called "supreme idiots"
(unless it's justified (if you do it, it's always justified)). Folks
who do spamming are simply called "idiots."
E-MAIL ADDRESS
If you stick a user name to the left of a host computer name and
if we separate the two names with an @, you get an E-mail address, like
collie@dog.wolf.net. Every E-mail address in the world is a
unique mailbox somewhere out there on the Net. Whew, whole lotta mail
boxes out there.
E-MAIL LIST
(Also called mail groups, listservs, and
majordomos.) You send E-mail to a group address, and it goes to
everyone subscribed to the group. Similarly, every E-mail that someone
sends to the group goes to you; it's a neat way to have conversations
on specialized topics (or just to socialize). You join by subscribing,
you unjoin by unsubscribing. Many e-mail lists are private (MDs like to
exchange secrets via private e-mail lists), and many others are open.
(There are a LOT of E-mail lists.) Just be careful, you can begin getting
a HUGE QUANTITY of mail after you join a popular mail list. Quickly.
(ADVICE--> Mail lists have TWO addresses. One address you use when you want everyone subscribed to the list to see what you have to say. The other is for administrivia... like subscribing and unsubscribing. If you send your unsubscribe request to the entire group, you'll likely be called an "idiot". But it happens. What will scar you for life is complaining bitterly to the entire group with several letters sent over a week or two complaining that you want to stop receiving "this junk.")
You can easily find most of the public e-mail groups. Just click here on
CataList, the official
catalog of LISTSERV lists.
ETHERNET
We can connect PCs that are fairly close together into a
network. Maybe they're all in the same office park. Connected in such a
network, they can easily exchange E-mail, they can share printers and
files, etc. Such a setup is called a Local Area Network, or a
LAN.
Ethernet is one type of LAN, one way of connecting the computers together. PCs connected by Ethernet can swap data at 10 million (or more) bits per second... pretty fast compared to the 56,600 bits per second folks using modems connect to the Net.
(IDEA--> Hey, what if we connected our LAN to an ISP with just one very fast connection, like a T-3? Then all the PCs on our LAN would have VERY fast access to the Net. Sounds great. Works great, too.)
(NUGGET OF KNOWLEDGE--> ISPs usually have several PCs (or bigger
computers than PCs) in the same room or building... and a cool way to
connect them, so that they can exchange data, is via ETHERNET... In fact,
Ethernet IS a popular way for ISPs to link their internal computers.) See
my excellent dog Wolf article How ISPs Work
for all the exciting details.)
EUDORA
Eudora is a popular E-mail client ("client" means that its a
program that runs on your PC) for retrieving your E-mail that's been queued
up (or "spooled") on your ISP's server out there somewhere on the Net; and
it's also great for sending E-mail. Eduora comes in "Lite" (free to
non-commercial users) and "Pro" (you pay a few $) versions, as well as
Pro with an advert on the screen (which comes free).
(Dog Wolf Suggests--> Start with Eudora Lite; then after a few months, you'll be able to tell if you really need "PRO." Or download the Pro version, and see if the small advert really bothers you.)
Releases of Eurora for the last few years have been able to interpret and display HTML documents, very similar to Web pages; most commonly, such documents are included with commercial mail... advertisements and coupons, etc.
(EGO TRIP--> Your importance on the Net is proportional to the amount of E-mail that you receive; ALWAYS claim that you get lots of E-mail (from friends... everybody gets lots of E-mail advertisements these days)... only your ISP knows for sure anyway, and it makes you sound important... and you can always subscribe to E-mail groups and get as much e-mail as you like.
(This hint does not apply to AOL, where EVERYONE who chats in chat rooms gets LOTS of E-mail. AOL allows up to seven screen names (as of January 2003); dedicate one screen name to E-mail only (never chat or post using this name); you will get no junk E-mail on this screen name... none of the spammers know it.)
(Again, be certain that you know how to un-subscribe from a mail group;
sending the word "unsubscribe" to everyone in the group will brand you as
a newbie (or worse, as an "idiot").)
FAQ
FAQ = Frequently Asked Questions (and their answers). You'll
see this all over the Net. FAQs are just a list of the most common questions
that folks ask along with their answers, written by people who got tired of
answering the same questions over and over... this encyclopedia is a kind of
FAQ.
Your ISP may have a FAQ on its Web site. Usenet newsgroups (message boards)
and IRC channels (chat rooms) frequently have FAQs. Asking a question that's
answered in the FAQ makes you an "idiot"; so read any FAQs before you ask a
question. (It's Ok to ask if there IS a FAQ and where it is... In fact, it
makes you look cool... because many "regulars" (the opposite of newbies) have
never bothered to read the FAQ.)
FINGER
Finger is a utility program that you can run as a client on
your PC to locate people on other sites (or you can type it on the command
line, if you have a UNIX shell account).
Type finger dog@wolf.net, and you may get the real name of the person with that E-mail address. You can see if "dog" has an account at domain "wolf.net." But only if wolf.net lets you. And only if the person with that E-mail address lets you.
You may also be able to see when that person logged on last, WHERE they
logged on FROM (good for identifying and locating unsophisticated trolls),
and other information. Finger is an attempt to link cyberspace with Reality.
(But it can't be done.)
FIREWALL
Sometimes, curious folks try to use the Internet to visit
the internal networks in banks, the CIA, hospitals, the Nuclear Defense
Agency, your ISP, you name it. A FIREWALL is a combination of programs
and computer hardware that folks use, in an attempt to prevent such visits
by the curious.
A firewall is designed to allow only specific kinds of messages, perhaps from specific folks, to flow between private (trusted) networks and the "untrusted" Internet.
Do firewalls work? Does the lock on your front door work? Yes, usually. But never say never. The CIA's Web page has been "enhanced" at least once.
If you subscribe to a cable ISP, you are sharing your cable connection with other folks in your neighborhood = potential for playfulness; have a router installed to act as your firewall. (The router will also allow you to connect 4 or more PCs to a single cable modem. And if you get a wireless router for a few dollars more, you can access the Internet from your laptop. Lying on the sofa or on your bed and chatting with friends on the Net can be cool.)
IMPRESS YOUR BANDICOOT--> Many folks wonder--> If I have a router between my PCs and my cable (or DSL) modem, do I still need firewall software? There are a number of answers to this question; Wolf has asked me to give you the CORRECT answer. OK...
If your router contains a decent hardware firewall, it will HIDE your PCs from hackers and spies and perverts out there on the Net... and it will make it a LOT harder for folks out there to attack your local network... it will surely hinder incoming intrusions and bozo attacks.
BUT... if you already have naughty programs ON your PCs, your router CANNOT prevent these rogue programs on your PCs from sending out data about your activities onto the Net; nor can it prevent rogue programs that have sneaked onto your PCs from launching attacks on other computers out there on the Net.
To gain OUTBOUND protection, you need a software firewall; we recommend
ZoneAlarm. AND ALSO... it never hurts to have an extra layer of protection...
BOTH hardware and software protection... both a router AND ZoneAlarm.
FLAME
A flame is a zinger, an attempt to denigrate or insult or
make someone look like an "idiot." And if you receive a flame (usually in
response to a post on Usenet), then you've been "flamed." [Actually, you
haven't, but thanks for attempting a viewpoint.] <--This is a flame, just
kind of a subtle one. More intense--> "You know, you CAN break the
Prozacs in half." Or... "What, they don't sell decaf in your trailer park?"
If you post a message to a mailgroup or a Usenet newsgroup that has nothing to do with its topic, you can usually expect a nasty E-mail containing a flame; no big deal. Flames upset some folks who are on the receiving end; others could not care less. The Net has elevated really great flaming (stuff beyond "You're an idiot") to a creative artform.
When two or more users flame each other in an escalating manner that threatens to continue into the next millennium, we have what is called a FLAME WAR. If you like flames and flame wars, check out Usenet newsgroup alt.flame (or enter some friendly Usenet newsgroup like alt.aol-sucks and say some nice things about AOL; affecting an arrogant, know-it-all, condescending, and pompous demeanor always helps.)
Use Web site www.dejanews.com to scan newsgroup
alt.aol-sucks from 1996-97 for some of the all-time great flames.
FLAT RATE
This is the account plan that most Internet Providers (ISPs)
offer (2002). It's the opposite of your long-distance telephone service,
where the longer you stay connected, the more you pay.
Flat rate is like an all-you-can-eat buffet... as long as you're hungry, you can stay and keep feasting on the Internet. However, you can't camp out there after dinner and wait for breakfast; when you're done, you leave (log off).
Flat rate is often called "unlimited," but "unmetered" is a better name. If you think you want to move into the restaurant and have ALL of your meals at the a.y.c.e. buffet, it's best to tell your ISP that you want a "dedicated" account... piggies can make the phone lines busy for others... sometimes. Just be honest here, and you'll be cool.
And note that a cable ISP allows you to stay connected to your ISP forever,
without any dial-up or login... it is the logical limit of flat-rate(if your
cable ISP is working correctly).
FTP
FTP is a service that the Internet provides, like E-mail or the Web. FTP is a
fast way to download stuff to your PC from some server out there on the Net
(pictures, programs, whatever you can find out there)... FTP is one of the
Net's vast treasure troves.
You can also use FTP to move stuff FROM your PC to some server out there on the Net. (You'll usually do this if you have a Web site; then, you'll want to "upload" stuff from your PC to your Web hosting service on the Net, for all the world to see).
IMPRESS YOUR LOCAL CONSTRUCTION WORKER--> FTP = File Transfer Protocol.
And see my excellent dog Wolf article
How The Net REALLY Works
for ALL the exciting details on FTP.)
GIF
GIF is a format for representing a picture on the Net (or on
a computer) in a file. GIFs are compressed, and so they're usually smaller
than pictures in many other formats (except for JPEGs, which are compressed
even more... so much that some of the color or detail has been thrown away,
though this may not be noticeable. Because JPEGs are even smaller than
GIFs, GIFs are becoming scarce these days (2002).
(IMPRESS YOUR DATE--> GIF = Graphic Interchange Format, JPEG = Joint
Photographic Experts Group.)
GOPHER
Use a gopher client program on your PC to connect to some
gopher server out there on the Net. Then pick an entry from the menu he gives
you. Pick another... the menus become more and more detailed. Ultimately,
you'll get the names of lots of files on some topic. Gophers are very cool,
but they have now (2002) been pushed aside 99% by the Web (sight and sound
and hypertext on the Net) together with search engines such as Google. As a
result, lots of stuff that you find using Gophers is old (but much is still
excellent, all the better for having been forgotten). Try it, you may like it;
especially if you're doing research, as opposed to surfing. And think of
gophers as what the Web was before 1995.
GUI
GUI stands for "Graphical User Interface," and it's pronounced
"goo'-ey." If a program on your PC is NOT GUI, then you communicate with it by
typing text on a command line. (This is called a "CLI" system, for "Command
Line Interface." GUI and CLI are "opposites.")
DOS isn't GUI; it's CLI. UNIX isn't GUI; it's a CLI, to name just two. Non-GUI is considered uncool today (2002) by many folks.
If your program or operating system IS GUI, you can click on things and drag and drop icons with your mouse pointer, or you can click on lists of menu items, or you can select menu items from your keyboard, or you can press a button on some toolbar. Windows is GUI, and Mac OS is GUI, to name just two. And programs that run on these are usually GUI also. And many folks today consider GUI cool. Some have never even seen a CLI program.
Reality check... While GUI is often very convenient, and while GUI is easy
for the newbie to use, command lines can input incredibly powerful commands
that can move large cyberspace mountains with just a few symbols, as in the
infamous DOS command-
DELTREE /Y \*.* (I am the thought you are
now thinking... DON'T TRY IT).
HOST
A host is computer on the Net that performs some service for us. Perhaps
it has files that it lets you download to your PC. Or it may retrieve
Web pages. Or it may send your E-mail out to folks. Or it posts your
Usenet articles. Or it lets you chat on IRC. Maybe it plays a game of
chess with you. And on and on... all of these are examples of hosts on
the Net.
IMPRESS YOUR LOVER--> The host is the computer out on the Net that
performs some service; but the program on that computer that actually
performs the service is called a "server," like a Web server.
HOST NAME
A host name is the name of a host computer out there somewhere
on the Net, usually the host computer that you want to reach. Host names look
something like dog.wolf.net. The dog part is the name of
a specific computer at location wolf.net.
HTH
Hope This Helps. A shorthand, often used sarcastically or
in a flame, at the end of a correction of another... or after an explanation.
Usually used in posts to Usenet or in E-mail.
Example... Folks who remember to break their Prozacs in half usually end up spelling "ferrette" (see your post) as "ferret." HTH. Now go home.
Or... What we learned about you, DAwn, is not that you changed nicks
on IRC, but that you're a liar. HTH. (You had to be there.)
HTML
HTML is the language your Web browser interprets. The nicely formatted
documents your browser returns to you were written (at least partly)
in HTML. And for the last few years, E-mail readers like Eudora and Outlook
have been able to display E-mail containing HTML... usually commercial
mailings with advertisements, coupons, etc.
In HTML, this definition looks like-->
<br><br><hr width="90%" size="3"><center></font>
HTML is the language your Web browser interprets. The nicely formatted
<p> In HTML, this definition looks like-->
<font size="+0">
[HTML snipped here to prevent infinite recursion and a possible black hole.]
<p>HTML</center><font face="Times Roman, Helvetica">
<p><IMG src="./smiley2.gif">
documents your browser returns to you were written (at least partly)
in HTML.
HTTP
A way for moving HYPERTEXT files around the Net. HTTP
is the way that most of the stuff moves about the Web. In fact, HTTP is the
underlying protocol for the Web.
(IMPRESS YOUR DATE--> HTTP = "HyperText Transfer Protocol.")
(IMPRESS YOUR LOVER--> There are four phases to HTTP (you can follow them on your browser's status bar at the bottom). 1.) Makes a connection with the specified server on some host computer; usually, your browser tries to make a connection with port 80 on that server. 2.) The request phase... your browser makes a request of the server. 3.) The server responds and sends some control information along with the requested page to your browser. And 4.) the close phase, initiated when the requested page is sent, or when you press stop on your browser.)
(Reality Check... someone realized that doing many connections and
disconnections, when most of the items retrieved were coming from the same
Web server, was kind of silly. And so HTTP version 1.1 added the ability
to maintain a socket connection and make multiple requests to a server with
just one connection.)
HYPERTEXT
Hypertext is text that has links to other files. This page has
some links that will take you to other documents (like the buttons at
the top and bottom). Click on a hypertext link, and you can retrieve another
document or picture or whatever.
ICQ
ICQ is a cute abbreviation for "I Seek You." You download the ICQ program,
and it tells you when your friends are on the Net... and then you can page
them and chat with them. (They too will need to download the ICQ program.)
With ICQ, you can also send files to your buddies; and lately, you can even
initiate voice and video sessions with your mates.
IE
IE (Internet Explorer) is the most popular Web browser (2002) and was
developed by Microsoft. IE is in many ways similar to Netscape, which
is now owned by AOL.
Both IE and Netscape are clients (programs that run on your PC). You tell your Web browser which Web server you want to access out there somewhere on the Net, and which page you want from the Web server. If all goes well (and it usually does), the server returns the page to your browser. And your browser then displays the page on your PC.
Thus, if you give your browser-
http://www.precisenetworking.com/~mcgatney/gloss.html, it will
try to get page gloss.html from directory mcgatney
out there on server www.precisenetworking.com.
IMHO
In my humble opinion. A shorthand used to indicate that the
writer is expressing a debatable opinion, as... "IMHO, dog Wolf has no equal
as both a philosopher and a lover." Also occasionally IMNSHO... "In my not
so humble opinion."
IMAP
When you send me an E-mail, your message is queued
(spooled) in my password protected mailbox somewhere out there on the Net
in what is usually called a "POP Mail Server."
To retrieve your letter (and all the others that have accumulated for me), I log onto the E-mail server at MY ISP, using MY e-mail client (like Eudora or Outlook); and, using the POP3 protocol, I check for letters, download any that are there, and delete them from my ISP's POP mail server. POP enables my desktop client, my Eudora or Outlook, to download my mail from some mail server out there on the Net.
OR... perhaps my ISP has the newer "IMAP mail server and archive," instead of a POP mail server. IMAP (Internet Message Access Protocol) servers can store mail just about forever. And I can view the headers first before downloading my mail, and so I can download only stuff that I really want to read, using an "IMAP Session," instead of POP3.
Another way to look at it is that IMAP permits a "client" E-mail program on your PC (like Eudora, or Outlook, or whatever) to access remote message stores at your ISP just as if they were local and on your PC.
IMAP is also superior to POP in another way... The widely used Post Office
Protocol (POP) works best when you download your mail to just ONE PC. POP
was designed to download your messages and then delete them from the mail
server. But this mode of access is not always cool with multiple computers,
since it tends to sprinkle messages across all of your PCs... not good. IMAP
allows massages to be selectively downloaded to selected PCs.
INTERNET
(It's also called The Net.)
A network is two or more computers connected together with a wire or by radio waves so that they can communicate and exchange data. This collection of computers and wires (or radio transmitters and receivers) we call a network (little "n" for "little network.")
The Internet is simply a bunch ( a BIG bunch) of these little networks connected together into a network of networks. The Internet is not the only "network of networks", but it's the BIGGEST. And every little net on The Internet communicates with every other little net using the TCP/IP language and the TCP/IP set of rules (protocols).
Actually, the Internet is a lot like the public switched telephone system,
except that it carries tiny data packets instead of voices (and in 2006, pictures
and live action). (Yeah, when you send an e-mail, it's torn up into lots of
tiny data packets, sent to its destination, and then reconstructed... the packets
don't even all have to take the same path... VOILA, it's magic.) And like the
phone system, the Internet covers the whole world; it's BIG business.
IRQ
Every PC has a bunch of things called IRQs. An IRQ is a
"phone line" that a peripheral (such as a modem or a hard disk) can use
to tell the main processor chip that it needs control of the system...
FAST. IRQs are a way for a device (keyboard, sound card, CD ROM, etc.) to
signal and interrupt your Intel Pentium IV processor, or whatever.
For instance, assuem that your modem has just received a character of data... it HAS to store it in your PCs memory (RAM) BEFORE the next character of data arrives. So like all good modems, it "raises" his IRQ. Each device has his own personal IRQ. And wham-o, the Intel or AMD (or whatever) processor chip stops whatever else it was processing and instead starts to handle this mundane but extremely time-critical task of retrieving the character from your modem.
This happens hundreds of times a second on your PC; and if all goes well... and it almost always does... you are never aware of your IRQs... these Interrupt Requests.
(Two devices can NEVER "share" an IRQ path. (Can two 4th grade students
agree that Brad will raise his hand when EITHER of them has something to say,
without creating chaos?) In your PC, when the processor looked to see what
the the device wanted that was SO important, it would find TWO devices and
get extremely confused. (Yes, you can assign two devices to one IRQ; and yes,
there will be chaos.))
ISP
So what's all this business about an ISP (Internet Service Provider), and why
do we need one?
It would be intensely cool if we could just install some program on our PCs that would allow our modems to dial up the Net directly.
But our modems connect to phone lines... to the switched public voice phone lines... phone lines which are analog and switched. We want to hear the weather forecast here, we dial 410-936-1212.
But if we want www.weather.com... with IP address 208.134.241.155 on the Net, can't we just dial with our modems to...? BZZZT, but thanks for playing...
Because our modems can't dial an IP address. They can only dial telephone numbers. And the Net is definitely NOT on the switched voice analog network, the public phone network that we all know and love and use to chat with Aunt Biddie. NO... The Internet lives on its own "semi-private" network.
And an ISP is the link, the interface, that lets folks with PCs and modems who have a connection to the regular telephone network connect to the Internet. An ISP interfaces between the public phone system (or some cable TV system) and the Internet's digital phone lines... digital phone lines that carry PACKETS on the Net instead of voice conversations.
When our modem dials our ISP, we get our own "Internet phone number" (called an IP address); then we can use software on our PC (called "clients") to connect to other computers somewhere out there on the Internet (and they can connect to us). For example, Netscape may ask some distant server for some Web page; the server sends the page to our PC.
Most ISPs also provide a "mail box" to save our e-mail, so that we don't
need to be connected to the Net constantly. And most ISPs provide a "newsfeed,"
so that we can get articles from Usenet. Many ISPs will also let us store our
Web pages on their servers, so that folks around the world can view them. Some
large ISPs are AT&T, MSN, and Earthlink.
INTRANET
A network is two or more computers connected togetherwith wires so
that they can exchange data with each other. They can used the IPX language
to talk to each other, or Ethernet, or TCP/IP, or whatever language they both
speak. Since we rarely connect more than a few thousand computers together in
a network, we call these networks "little networks."
Now... suppose that you and I both have our computers on our own little networks. My computers use the IPX language to communicate with each other, and yours use the Ethernet language to communicate with each other. And suppose that you and I decide that we want our two "little networks" to communicate with each other; that is, I want one of the computers on my little network to exchange data with one of the computers on your little network... in effect, you and I want to make a "network of networks."
And suppose further that you and I decide that our two "little networks" will talk to each other using the TCP/IP language. VOILA... we have just created an internet... a network of networks, where the little networks communicate with other little networks using TCP/IP.
Ok, that's an internet... and the biggest internet of them all is called the Internet (capital "I"), or The Net. Millions and millions of computers talking to each other, exchanging e-mail, retrieving pages from the Web, allowing folks to chat using IRC, whatever. Tada.
To state it another way... an inTERnet is what you get when you connect together a bunch of little networks, and each little network speaks the TCP/IP language to the other little networks when it transfers data between them. All the little networks on the InTERnet speak the same language when they communicate with each other; they follow a set of rules (a "protocol") called TCP/IP.
And remember, the computers on each little networks can speak anything they like when they exchange data internally... IPX, Swahili, Ethernet, even TCP/IP will work... you name it... whatever internal protocol they like.
BUT... if computers on a little network speak TCP/IP when they communicate with other computers on the SAME little network, then that little network is called an inTRAnet. In other words, an inTRAnet is a little network that speaks TCP/IP when its own computers communicate with each other... a little network where all its own computers use the TCP/IP protocol when they exchange data.
An inTRAnet also may be connected to the big InTERnet. Or it may not... it may be a private little network.
Thus, a the computers on a LAN (Local Area Network)... where the computers communicate with each other using the TCP/IP protocol, is an INTRANET. Tada.
(IMPRESS YOUR FERRET--> If you connect two or more inTRAnets together, and if the inTRAnets communicate with each other using TCP/IP, then you get what's called an EXTRAnet. Every computer, no matter which network it is on in an EXTRAnet, communicates with every other computer on the EXTRAnet using the TCP/IP protocol.
Like, maybe I'm Ford Motors, and I have an inTRAnet connecting all my
internal company computers, and all the companies that supply me with parts
also have inTRAnets connecting their computers; and if we connect all of
these inTRAnets together using TCP/IP, then wham... we have just created
an EXTRAnet... in effect, a little private little version of The Net. Very
cool.)
IP ADDRESS
A thing that looks like nnn.nnn.nnn.nnn, where
each nnn is some number from 0-255 (like 206.80.150.1), is called
an IP address. Every computer on the Net has a unique IP address. (It's the
same as your telephone number on the telephone net.) Host names must first
be converted to an IP addresses before TCP/IP (and you) can use them.
There are STATIC IP addresses (you get the same IP number every
time you log onto your ISP), and DYNAMIC IP addresses (you don't).
Because folks have trouble remembering IP addresses like 204.168.83.2, many
IP addresses are represented by host domain names that are easier to remember.
So you may type in host name www.dogwolf.com on your browser, but
204.113.5.87 (the IP address for this host name) will go out onto
the Net.
IRC
IRC is a service on the Net that can be extremely valuable for folks who
know how to use it. IRC lets you chat with other folks (one or many others)
online in real time; and it allows you to exchange files with other people
somewhere out there.
Like everything on the Net, you crank up your IRC client (program) on your PC (mIRC is a popular client), and then you connect to an IRC server "out there" somewhere on the Net. Then you can create a "channel," and once you do that, other folks can drop in and chat with you and with each other. Or you can can drop into an existing channel when you join it with your IRC server.
There are IRC servers around the world, and they're getting increasingly busy. Groups of servers then can link to each other. EFNet is the biggest group of servers. The Undernet is another popular group of servers, along with DalNet.
BUT... if I'm on channel #DAwn on EFNet, and you enter channel #DAwn on the Undernet, we won't even see each other, and we can't talk. Parallel universes. Each group of servers is its own cyberverse of thousands of chat channels. It's a big galaxy out there waiting to be explored, which is part of the fascination of IRC and the Net.
Chat on AOL is like hamburger compared to the IRC filet mignon. Get to know some folks, and they'll give you the names of some servers that comprise "secret" IRC nets. And you never know who you'll meet (or have met) on IRC. Literally. (Why, you could even meet ME some night out on IRC cyberverse. What a treat.)
And no, you cannot access chat in AOL's chat rooms using IRC, nor can you
get to IRC from AOL's chat rooms. Two more separate universes.
ISDN
IMPRESS YOUR SATURDAY NIGHT DATE--> ISDN = Integrated
Services Digital Network. The "integrated" part refers to ISDN's ability
to deliver two simultaneous connections of data, voice, fax, video...
whatever.
Why ISDN? Your plain old analog telephone service was never intended to connect you to the Net. ISDN to the rescue. You get it from the same phone company, but it transmits stuff in digital format across the phone lines. Because of this, ISDN transmits data much more reliably than an analog line. And because your data stays digital, there's no need to have a modem with ISDN... just plug your ISDN adapter into a phone jack.
The most common ISDN configuration for Net access is called BRI (Basic Rate Interface). An ISDN BRI connection supports TWO 64,000 bit per second channels over a regular phone line. To get BRI ISDN service (yes, you guessed it), you usually have to be within 18,000 feet of your phone local phone company's central office building. And you'll need an ISDN terminal adapter and an ISDN Router at your PC.
An ISDN BRI configuration also includes a 16,000 bps channel that's used for signaling between your home and the phone company. By combining both of the 64 kbps channels, you can send and receive data to/from the Net at 128 kbps (or using compression, as fast as 250,000 bps). And unlike the 30 to 60 seconds required to set up a call through a modem on an analog line, because IDSN uses a separate channel for signaling, it's ready to go in about 2 seconds.
Some ISPs charge a little more for a 64k ISDN connection, others do not. Most ISPs will charge about $30-40/ mo for a 128k ISDN connection. And of course you also have to pay your phone company for the ISDN phone line.
Today (2002), the cable ISP has taken over ISDN's spot in the home
(assuming it ever had one... many folks think ISDN just took too long to get
its act together) for folks who want to connect instantaneously and receive
data from the Net fast. (Cable is very fast when it works... an entire new
release of AOL can be downloaded to your PC in a minute or two with a cable
ISP.)
JAVA
Java is a "language" that programs can be written in,
like COBOL. But unlike COBOL, Java is intended to be downloaded to your PC
from Web sites somewhere out there on the Net (without infecting your
PC with viruses).
Little Java programs are called APPLETS, and they can be quickly downloaded to your PC. Using Java applets, Web pages can do weird and exotic stuff, like displaying animations. And each applet adds new and exciting features, on the fly, to the Web. In fact, Java programs can do almost anything that "ordinary" programs can do; and then, these Java programs can be inserted into a Web page... these are truly exciting times in which to live.
NOTE--> Java and JavaScript are not the same. JavaScript resembles
Java, but the difference is that Java is a general purpose object language,
while JavaScript is a quicker and simpler language for enhancing your
Web pages.
JAVA BEANS
A Java Bean is a reusable software component that works with
Java. Reusable component? Like the tires on your car- Goodyear, Michelin...
they all work because they all follow the standards. But Java applets don't
always work well together.
BUT... Java Beans fixes this problem by standardizing things. For example, you can tie an Alarm Java Bean to the contents of a Spreadsheet Java Bean, which can then be tied to an On-line Stock Feed Java Bean. And as the stock prices change, the values in the spreadsheet change... and finally the Alarm goes off if any watched stock changes significantly.
Using Java Beans, applications are assembled from reusable components,
not written from scratch. That's all, folks.
KLINE
If you're banned from an IRC channel or from an entire IRC server,
you've been K-lined, or klined. Usually, klining is not a personal thing;
the folks running an IRC channel or or IRC server typically have had a bad
experience with customers from your ISP or from your commercial service like
AOL), and so they've banned all of them.
LAMER
A Netizen (citizen of the Net) who behaves in a foolish or uneducated way is
often called a "lamer." Newbies (newcomers to the Net) are often called lamers,
as are AOL users. (The latter are occasionally called AOLamers).
LAN
A LAN is a network that connects computers in an office, in
a building, or in a few buildings that are relatively close together.
LAN stands for Local Area Network. Computers on a LAN can share printers,
and they can share files.
If the computers on a LAN communicate with each other using the TCP/IP protocol, the LAN is called an Intranet. Ethernet is the most popular protocol for LAN computers to use when communicating with each other.
Many LANs have a single high speed cable (like a T-1) connecting them to
the Internet... so that every computer on the LAN gets very high speed
access.
LURKER
Frustrated Netizens who peek into your bedroom in the
middle of the night? Nah... just folks who read discussions on Usenet
newsgroups but don't participate by posting replies. Good netiquette
says that you should lurk for a bit before posting to a newsgroup;
if you don't, claim you have been lurking anyway. (No one knows.)
MAIL-BOMB
Mail-bombing is sending someone a large quantity of unsolicited e-mail,
usually garbage and usually as a "punishment". (Mail-bombers are often
"idiots," but so are some of those who provoke it (sometimes).)
HINT--> Don't bother mail-bombing folks with ISP shell accounts. Shell accounts run on UNIX-based computers; and UNIX has E-mail readers like "PINE," which while not GUI (you have to type line commands) can delete huge amounts of E-mail with just one or two commands, without you ever having to download it.
In 1996, many Usenet newsgroups and various hapless Netizens were targetted by one or more mail-bombers using a special Usenet server to throw dozens of tens of thousands of messages at various hapless recipients and newsgroups... possibly the worst mail-bombing ever. This incident and the associated technique used by the mail-bomber have become known as the "McGatney Bomb" (no relation); it affected many locations worldwide.
Games for the emotionally mature and mentally secure, yes? Nope.
MAIL-BOX
It's just like the postal box that you rent in the post office. Since your
PC doesn't run ALL the time, your ISP saves all your incoming e-mail into
some disk space on a mail server computer, reserved just for you, out there
somewhere on the Net; this disk space out there on the Net, on some mail
server computer, is called your mail box. (To be precise, the mail server
is a program running on some computer "out there" on the Net. This program
directs your mail to your dedicated space... your mailbox... on the
computer's hard drive.)
NOTE that your mail box is NOT on your PC. When we turn on our PCs and
connect to our ISPs and start up our Outlook or Eudora e-mail program, then
we can download the mail from our mailbox "out there" somewhere to the disk
on our PC; and once it's on our PC, Eudora or Outlook lets us read it.
MEGA-POP
Ok... let's assume that we're an ISP in Mytown, and we want to extend
service to Littletown. We lease some phone lines there so folks can dial in,
we install modems in a phone exchange in Littletown, and we connect the modems
to our main facility back home with a dedicated wide-band phone line. And we
hope that the location of this new "POP" (point of presence) isn't too far
from our home base to drive there in the middle of the night to fix something.
Pretty straightforward stuff.
But now assume we now want to extend our service to Bigtown, population 10 million. The main problem with entering the Bigtown market and offering access to all those new customers is that MANY local POPS are required, like say 30; because customers hate making toll calls to ISPs. They want to call local numbers. And we might need 30 local numbers so that no one in Bigtown has to make a toll call to call one of our modems.
Well, until recently, our ISP would need modems and phone lines in 30 different physical locations to support all of Bigtown. And we'd have to run dedicated wide-band phone lines (like T-1s) to each phone exchange, rent space, install modems, juggle the modems with the demand in each location... it used to be the stuff that ISP nightmares were made of.
Enter the megapop. A megapop lets us support all of Bigtown with just ONE BIG POP. The megapop (often a service provided by a local phone company) provides all 30 dial-up numbers at 30 local exchanges all across Bigtown. Our customers calls to ANY of these exchanges are routed by the megapop to just ONE digital connection... so that our ISP can put ALL of its modems here, and then we run our dedicated line from that connection point to our home base, and voila... we're in business.
Because the megapop routes all of our calls to one point, our ISP can
set up shop in Bigtown just like we did in Littletown. Simple? Yes.
MIME
E-mail was intended to send only text. But you can trick E-mail
and send pictures and programs and stuff like that as attachments to your
text letters IF the mail programs at both ends support MIME. MIME is a set
of rules (a protocol) for E-mail that lets us send non-text data, like graphics,
audio, video and other "binary" types of files.
An e-mail program like Eudora is said to be "MIME Compliant" if it can send and receive files using the MIME standard. When non-text files are sent using the MIME standard, they get converted (encoded) into text... although the resulting text looks like some gerbil walked across the keyboard.
Besides e-mail, the MIME standard is also used by Web Servers to identify
the files they are sending to our Web browsers; in this way, new file formats
can be accommodated simply by updating our browsers' list of "MIME-Types"
along with the software for handling each type. (IMPRESS YOUR S.O.--> MIME =
Multi-purpose Internet Mail Extensions.)
mIRC
A cool client program (many say the best) to run on your PC if you want to
chat with others on the Net using IRC (Internet Relay Chat). But no, you
can't use IRC to access AOL's chatrooms for free; and no, you can't use AOL's
chatrooms to access IRC... different bizarro worlds.
MODEM
A modem is a piece of hardware that lets your computer talk to another
computer using the regular telephone system or your cable TV line. A modem
is like your computer's handheld telephone. And if you have an ISP,
modems can connect your PC to the Net using your phone line or your cable
TV line.
MUSH
"MUltiuser Shared Hallucinations." MUSH are (is?) fantasy role playing games,
like Dungeons and Dragons. Mush is very popular on the Net, and you can play
by IRC, Telnet, and (yes) even by E-mail. Many otherwise serious, educated,
and normal men and women are deeply into MUSH. (No, I don't know why.)
NAP
"Network Access Point." Ever see a traffic circle? (Yeah,
they take some getting used to.) Several roads all run into a circle. You
come in on one, and you circle around until you can get to the road you
want to get out on. A NAP is exactly the same thing.
Big networks come in, drop their data into the NAP, and it circles around to another network that it wants to get onto. And just like the highway NAP, when traffic is heavy, it doesn't work too well. NAPs are one way that networks (highways) owned by different ISPs can communicate with each other... so that E-mail can get from aardvark.net customers to ferret.com customers, for example.
Sometimes, NAPs are high-speed cables and routers that actually circle
a city; othertimes, they are individual buildings filled with cables and
hardware
NETCOP
If you do something on the Net that annoys somebody, they may
report you to your ISP (or on AOL, to the ubiquitous "TOS" (Terms Of
Service). This is called netcopping (sometimes writen as net.copping);
and the person doing the reporting is called a "netcop."
Many folks on the Net dislike netcops. Netcopping is normally reserved for serious offenses (like spamming), since you can easily make longterm enemies by netcopping folks... which can provoke counter-netcopping and mail-bombing... which can all be rather amusing, when you're watching from afar and not directly involved.
All of this stuff helps to give the Net its unique flavor. Right.
NETSCAPE
A popular Web browser; you give your browser
the Web server and file you want to retrieve (like www.yahoo.com/ferrets.html),
and Netscape displays the file... if it's there and you're authorized to
see it.
Netscape also can read from and post articles in Usenet newsgroups; and
it can send and receive e-mail. Today (2001), Netscape is owned by America
online and is second in popularity to IE (Internet Explorer), used by AOL.
(No, don't ask.)
NETIQUETTE
Netiquette is using the Internet in a polite manner. The Net is very free,
so it's important not to abuse it in ways that limit the enjoyment of
others. "Don't send unsolicited junk mail to lots of Netizens" is an
example of netiquette. We've tried to list most of the major newbie
"no-no's" of netiquette throughout this encyc