
by Reno Bailey
When we first started this website, I was explaining
it to Mama, and she asked me, “When is it on?”
I said, “Mama, it's on all the time.”
“Well,” she asked, “how long is it?”
“It's as long as it takes to read the articles
and look at the pictures,” I explained. “It's like a library.
You just go there and look at and read whatever you like, and leave
whenever you like.”
Mama has a better understanding of it now, since Guy
and Helen Hamrick were kind enough to invite her over to
their
house and take her on a tour of “Remember Cliffside.”
I got to thinking. What do we really know about this
new-fangled way of doing and learning things? I'll tell you all I
know, which isn't much. Maybe in the telling, I'll understand it too.
While we slept, they've wired our country and much
of the world, connecting computers everywhere by constructing vast
networks, over telephone lines, fiber optic cable and satellites.
ISPS
Here while back, you went down to Circuit City or
Office Depot and bought yourself a computer. Then you found a company
(or it found you) to hook you up to the internet. These companies
are called Internet Service Providers (ISPs). There are hundreds of
them. The big boys are AOL, Time-Warner, AT&T, Earthlink, and
others. And there are smaller, more localized ones like Blue Ridge
and RCFI, to name two in Rutherford County.
SERVERS
To better understand what a websitesuch as RememberCliffside.comis,
think of it in terms of those mini-storage businesses that have sprung
up like weeds in every town, big and small. You sign up with a company
for a proscribed space, store your stuff, and pay a certain amount
per month. The storage buildings in this context are called servers,
or high-capacity, high-speed computers. The larger data storage companies
have server “farms,” where great numbers of computers are
concentrated.
One
of these space providers is Yahoo! Geocities, the one we chose to
hold the “stuff” of Remember Cliffside. Their servers, at
least the one we're using, happen to be in Sunnyvale, California (in
“Silicon Valley,” just south of San Francisco). We contracted
for 25 megabytes of space, with a minimal amount of traffic, or daily
visitors to the site. Currently, we have about 140 visitors on any
given day. If that number shot up to, say, 5000 a day, Yahoo! would
quickly come knocking on our door, demanding more money.
We selected another, smaller company to handle our
guestbook services, an outfit called TheGuestBook.com, whose server
is in Darien, Connecticut. (By the way, when you make a guest book
entry, you may notice the time stamped on the entry is a little odd.
For example, if you are in the Eastern time zone in the US [EDT],
and enter a message at 6:02PM on Thursday, May 9, local time, the
date and time stamp on the message will be: Fri May 10 00:21:02 2002.
In other words, six hours later than your local time.That's Greenwich
Mean Time [GMT], or the current time/date in the time zone of Greenwich,
England. This is a reference method used by the military, and other
concerns, to standardize times for communicators across multiple zones. Read more
about the world's time zones.)
Are we having fun yet?
NETWORKS
So, you go to your computer, start your internet browser,
and click the Remember Cliffside link in your Favorites list. What
happens then? Your ISP starts a process that is, essentially, a journey.
It connects you to your destination (the server) by the quickest route
possible. The server responds, sending your requested information
back to you, again on the quickest route.
Actually your ISP puts your request on a network,
which will be switched to another network, then another and another.
It's like shipping something by train: Your shipment starts out on
the Seaboard line, but in New Orleans it's put on the Santa Fe line,
then, in Cheyenne, it's moved to the Union Pacific. Some of these
“lines” (or “networks” in the internet context)
are named AOL Transit Data Network, Qwest, Colorado Super Net, Road
Runner Net, Maxim, etc. There are dozens, perhaps hundreds of them.
The cities in this metaphor are like hubs, where one network turns
the data over to another.
Now, within a network there are connection points
called “nodes” which work like relays. Equate this scheme
to that Seaboard train running to New Orleans. First it goes to Spartanburg,
S.C., where your shipment is handed off to another train, which takes
it as far as Atlanta, where it's switched to a Birmingham-bound train,
and so forth. These nodes are also computers (special servers, in
fact, called “routers”), located in computer centers along
the way, many on college campuses. Their purpose is to recalculate
the route, based on traffic patterns, and maintain the integrity of
the data throughout the journey.
An average long-distance request, say from Charlotte
(where I live) to Sunnyvale, will go through a couple of hubs, several
networks an
d
many nodes. When I visit the Remember Cliffside site, the request
usually travels through about 20 nodes, hitting Atlanta and perhaps
Dallas-Ft. Worth (important hub sites), then directly to San Jose,
California, where it's then bounced next door to Sunnyvale. How do
I know this? There are software programs you can use to visually plot
the route of a request from your computer to the server. And it gives
you, in milliseconds, the time it takes to travel between nodes. (You
can examine each node's information, learning its exact location and
which network it's serving.) But the exact route of a given request
depends on the current volume of traffic. During heavy traffic periods,
the request might jump up to Chicago, then down to Houston, or any
which way. (See route map.) For example, sometimes, when you access
amazon.com, if their servers in Seattle are handling heavy traffic,
they will bounce your request all the way back across the continent
to Montreal! If you're curious about all this, download one of these programs and try it on your own computer. (Look for a
free 30-day trial option.) If you've been experiencing slow service
from your ISP, this could show you where the bottleneck is. What you
could do about it, other than complain to your ISP, is hard to guess.
WHAT IS A REQUEST?
When you submit a request, what are you requesting?
You're simply asking the server to show you the “home” (or
front) page of a particular website. (A page and each image on it
[buttons, pictures, etc.] are actually small, separate computer files.)
In response to your request, that home page file, and all other files
associated with it, are sent to, and stored on, your computer. (They're
considered temporary files, but, unless you delete them, they'll stay
on your computer until they're overwritten by a newer file with the
same name.)
Once the home page (in our case that file is named
“index.html”) is on your computer, you will use buttons
(such as “Memories” or “Town Map”) or text links
to connect to other pages on that website. To click on a link is to
send a request for a specific page.
If you send a request to view, say, the “Memories”
page, the server looks for its file (named memories.html) on your
computer's hard drive. If it doesn't find it, the server will immediately
send the file to you. If it does find it on your computer,
it checks the file's modification date and time. If the file on the
server is newer, it will send your computer the new version.
THE CARE AND FEEDING OF A WEBSITE
Every individual web “page” that you view
is a set of files. When the webmasteryours trulycreates
new pages (by writing text, selecting and cropping pictures, and designing
the layout using a language called “HTML”), he “pushes
up” (copies) these new files from his computer to the server
with a communications program
that
uses something called “FTP” (File Transfer Protocol). He
must push up not only the HTML file for each page, but also the files
for all images used by the pages. “Remember Cliffside” is
comprised of well over 1,000 files, using about half our allocated
25 megabytes of space. (A megabyte is the space required to handle
about one million characters.) If we should exceed the allocated spaceas
we are likely to dothe rent will go up.
Like a Field of Dreams, what if you build a website
and nobody comes? That will happen unless people somehow learn that
your site exists. That's a whole 'nother problem we'll discuss some
other time.
For a more in-depth (and likely more accurate) description
of web methods and issues, and many other things, visit the website How
Things Work. Pack a lunch, and be prepared to spend the day.
Aren't you glad we cleared all this up?