February 6 ITU press release on V.90 standard.
Most K56Flex modems are based on the Rockwell chipset. Many will need an "Extra settings" init string. Rockwell quick start.
K56Flex modems based on the Lucent chipset will need the latest driver. Lucent quick start.
Optimum performance may require additional tuning.
Some phone lines will not support any kind of 56k connection. Why some callers can't get 56k connects.
With mature technologies like 28.8/33.6 dialup, you can can pretty much plunk a modem into your computer and expect to get a good connection over any decent phone call. It wasn't always like this, and it's not like that yet for 56k dialup.
In the early days of 28.8 modems - and 14.4 modems before them - there was often a bit of futzing needed to get good connections, especially between modems of different brands. Now the futzing needed for older modems is known and built into Windows 95. New modems don't need any, because modem manufacturers have converged on common ways of doing things. They've even stopped including manuals with modems to tell you how to do the futzing.
We will reach that point with V.90, probably as quickly as we did with V.34 (the 28.8k modem standard), but right now 56k dialup is at the leading edge, where making your modem work its best - or sometimes even work at all - means twiddling with its adjustments and the software that drives it.
All K56Flex modems are built using one of two chipsets, one from Lucent Technologies and the other from Rockwell Semiconductor Systems.
The chipset used in making a modem determines many of the characteristics of a modem. In particular, the chipset determines most things about how a modem can be tuned.
If you don't know what chipset is used in your K56Flex modem, you most likely have a Rockwell-based modem.
Modems using the Rockwell chipset include Acer, Hayes, Motorola (some models), Practical Peripherals (PPI), Supra, Zoltrix, and Zoom, and some others. Most "no name" modems use the Rockwell chipset too.
With the exception of a few very early beta models, these modems are all software-upgradeable by loading new code into them. Your first step should be to download the most recent modem code from the manufacturer's website. We maintain a set of links to the major manufacturers' download pages on our things for members page. The upgrades come packaged in self-installing programs.
Most Lucent-based user modems are partially software modems, meaning
much of the work is done by the driver. Getting the best performance
comes from using the latest driver.
Hewlett Packard uses the Lucent chipset and has instructions and the
latest driver on its website. The instructions were written for
Hewlett Packard systems but apply to any Windows 95 system.
As of 4/30/98 the update page still walks you through to a download of
driver version 4.15, which is old (dated 10/17/97), so we have
provided a link to download driver version 4.31 dated 4/23/98. We
recommend reading the driver update page instructions but downloading
the latest driver.
Our server modems are Lucent modems, but the digital server end of 56k
dialup is very different from the analog user end. Our server modem
experience does not carry over as education about Lucent user modems.
Modems negotiate an initial connection speed, but they don't just stay
at that speed throughout a session. They monitor the connection
quality and renegotiate the speed when they need to go slower
or think they could go faster. They will sometimes retrain as
if they were just connecting, which can result in a protocol change as
well as a speed change.
Renegotiations happen a lot. They happen quickly, but they do take a
little time and cost you throughput if they happen too often.
Retrains normally happen less often, but they cause long pauses when
they do occur.
You may get better performance if you tell your modem not to try to
use the highest speeds. For example, if you find you connect at
speeds ranging from 44k to 50k, your 50k connections may be dropping
to 44k fairly quickly, and regardless of your initial speed
your modem may be spending a lot of time renegotiating up to a higher
speed and then renegotiating right back down.
In that case, telling your modem not to bother trying to go faster
than the low end of your range may significantly improve your
performance. With a Rockwell modem you could do this by
changing/adding the init string segment below. The highlighted
"44000" would limit a modem to 44k.
However, the variation in your initial connection speed may also be
due to variation in the quality of the phone connection you get. In
that case, limiting your maximum speed means you won't do as well as
you could on your best phone calls.
All you can do is try it both ways and go by the general rule of
tuning: if you can't tell which works better, it doesn't matter which
works better.
For those who want to try rolling their own tuning, Zoltrix has an
excellent Web page giving the "AT" command set for the Rockwell
chipset, which can be used to adjust minute details of modem behavior.
This is definitely not for novices. However, scanning this page a
time or two will help develop an appreciation for the complexity
involved in making modems work.
NetHeaven support,
support@NetHeaven.com