The Online World resources handbook

Cheaper and better communication http://home.eunet.no/~presno/bok/13.html
Capture trip information to a log file. Register the following information: * number of
minutes connected * modem speed * number of characters sent. Some communication
programs can do this automatically for you.
On services charging for time and volume
Log the following information: * number of minutes connected * modem speed *
number of segments or packets (measurements of volume) You need these numbers to
estimate the average volume of data transferred by minute. Here are some general
experiences and hints:
Long streams of data without stops are cheaper through services that only charge by
the minute. Retrieving software is a typical high volume application.
Trips that include navigation from conference to conference, with a little bit of up
and downloading here and there, make the average transfer speed fall dramatically.
Surfing the World Wide Web is usually in the same class. It's like driving through a big
city at 150 kilometers per hour. Red lights will considerably reduce your average speed.
The actual transferred volume of text per minute will differ from place to place
(geographically), and often also from call to call. It depends on factors like:
How fast you can enter commands and how much time you spend staring at the
display before pressing keys,
How long it takes for an online service to react to your commands. For example,
the response time on CompuServe at 04:00 GMT on a Friday morning (it is
evening in the U.S.) is much worse than at 10:30 GMT on a Sunday morning. By
now, most North American users are asleep.
The load on your packet data network while you use the service (or the amount of
noise and retransmission, when calling direct),
The type of modem you are using (speed, compression level),
The number of commands you (or your scripts) have to enter during your online
visit. An increase in the number of commands reduces the average transfer speed.
The amount of transfer overhead for color and screen handling (like, VT 100 or
html codes) that is transferred with your text.
Your use of menus and help texts while online, or whether you come as "expert"
with a minimum of prompts.
Whether your browser is set to capture all pictures and sound files that it comes
across, or just the text.
It is impossible to calculate the practical effects of these items. You will just have to bear
them in mind when estimating typical jobs, measuring speeds, calculating costs, and
comparing networks.
Finding the optimal network for your needs will take time, but it is well worth the
effort. Expect the figures to surprise you.
The network services in this chapter will often give you better quality transfers than
a direct call. On the other hand, calling direct may give more characters transferred per
minute. The average speed may drop dramatically when using packet data services.
The cost of using PDN services
Most commercial online services can be reached through national PDNs, but you may
have problems finding the correct NUA (Network User Address) to get there. Your PDN
may not have a directory of available "electronic telephone numbers" for you to consult.
The Norwegian PDN, Datapak, used to be my only alternative for access to foreign
online services. At the time, I thought the cost was acceptable. Not so any more.
My applications require that data be pumped back and forth at maximum speed. On
network services charging by a combination of volume and time, 80 percent of my costs
are typically for volume, while 20 percent is for connect time.
When I logged out after a successful visit to CompuServe through Datapak, the two
services gave similar reports:
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