Soft V92 Dat Fax Modem connecting at 33.6 kbps only !

W

Wiseman

Hi,

I've installed a new modem in my pc but it doesn't go beyond 33.6 kbps. I've
tried with various service providers but this is the top speed it can
connect to. I don't understand this behaviours because I have an old modem
that goes beyond 45 kbps. Any clues on how to speed up this device ?

Regards.

Wiseman



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Z

Zilog Jones

Hi,

I've installed a new modem in my pc but it doesn't go beyond 33.6 kbps.
I've
tried with various service providers but this is the top speed it can
connect to. I don't understand this behaviours because I have an old
modem
that goes beyond 45 kbps. Any clues on how to speed up this device ?

Might just be the quality of your line that is limiting the speed that
much, and sounds quite plausible if you're over 10-15km away from your
nearest exchange - maybe your old modem was just better at dealing with
this?
 
P

Paul

Hi,

I've installed a new modem in my pc but it doesn't go beyond 33.6 kbps. I've
tried with various service providers but this is the top speed it can
connect to. I don't understand this behaviours because I have an old modem
that goes beyond 45 kbps. Any clues on how to speed up this device ?

Regards.

Wiseman

Modems use the AT command set. The "dialing string" contains commands
to configure the modem. You start by examining the dialing string,
to see what commands are being issued, and whether they are appropriate
for the modem or not. You need documentation for the modem, as
to what commands it supports and what options are available.
For a really cheap modem, where printed manuals might cost more
to make than the modem, you might end up searching on the web for
such a manual.

A previous generation of modem operated at 33.6K up and 33.6K down.
There is usually an option available in the command string, to
make the modem behave like the older standard. A reason for
using such an option, is to speed up the negotiation phase, if
you were connecting to a 33.6K max modem pool. If a 56K down modem,
is used with a slower modem pool, it can take 30 seconds for
the modem to step through the various standards, until both ends
of the link agree on a speed. It is for that reason, that
the command set has options to restrict what standards your
end of the link attempts to use.

If most of the "modem" is implemented in software, it is also
remotely possible, that with the wrong software loaded, the
software is actually performing as a 33.6K modem. Make sure
you have the right software for the modem. If this modem is on
a PCI card, it should have a PCI/VEN/subsys enumeration, and
researching the numbers associated with the enumeration may
tell you what standards the modem is intended for. (I.e. The
model of modem may be artificially limited in connect speed,
by means of the enumeration of the card - if say the manufacturer
makes several versions of the same basic PCI card, some
being sold for less than others. The software may be used to
make the distinction between cards.)

In terms of perceived value, a bare card is virtually worthless.
A modem card that comes with a CD software installer is more
valuable, because you don't have to search the web for the
right software. And if it comes in a retail package with an
actual manual (complete with command set documentation), then
that is a miracle :)

Good luck - with modems, you'll need it.
Paul
 
W

Wiseman

Thank you very much for your time and explanation.


Paul said:
Modems use the AT command set. The "dialing string" contains commands
to configure the modem. You start by examining the dialing string,
to see what commands are being issued, and whether they are appropriate
for the modem or not. You need documentation for the modem, as
to what commands it supports and what options are available.
For a really cheap modem, where printed manuals might cost more
to make than the modem, you might end up searching on the web for
such a manual.

A previous generation of modem operated at 33.6K up and 33.6K down.
There is usually an option available in the command string, to
make the modem behave like the older standard. A reason for
using such an option, is to speed up the negotiation phase, if
you were connecting to a 33.6K max modem pool. If a 56K down modem,
is used with a slower modem pool, it can take 30 seconds for
the modem to step through the various standards, until both ends
of the link agree on a speed. It is for that reason, that
the command set has options to restrict what standards your
end of the link attempts to use.

If most of the "modem" is implemented in software, it is also
remotely possible, that with the wrong software loaded, the
software is actually performing as a 33.6K modem. Make sure
you have the right software for the modem. If this modem is on
a PCI card, it should have a PCI/VEN/subsys enumeration, and
researching the numbers associated with the enumeration may
tell you what standards the modem is intended for. (I.e. The
model of modem may be artificially limited in connect speed,
by means of the enumeration of the card - if say the manufacturer
makes several versions of the same basic PCI card, some
being sold for less than others. The software may be used to
make the distinction between cards.)

In terms of perceived value, a bare card is virtually worthless.
A modem card that comes with a CD software installer is more
valuable, because you don't have to search the web for the
right software. And if it comes in a retail package with an
actual manual (complete with command set documentation), then
that is a miracle :)

Good luck - with modems, you'll need it.
Paul



Inviato da X-Privat.Org - Registrazione gratuita http://www.x-privat.org/join.php
 
P

Paul

Thank you very much for your time and explanation.

I don't know exactly what is wrong with your modem, but the
magic value "33.6" doesn't generally pop up because of line
trouble. You know that the 45K you normally see, is a measure
of the phone line quality, while 33.6 is exactly the value of
the next modem standard down from 56K (called V34). That is
what makes me suspect the modem is not behaving as a 56K modem,
either because the dialing string says behave like a 33.6K, or
the modem driver thinks it is supposed to run at a max of 33.6K.

If you are familiar with the sounds that the monitor speaker
make on a 56K modem, you could probably tell whether it is
trying to connect at 56K or not. (Those boing sounds for one.)
But that is not a very scientific method.

Good documentation will tell you more than a table like the
one shown on this web page. The MS command has options, and
normally there is a whole page describing those options.

http://www.digistar.mb.ca/client/modemcomset.htm

For example, look on this page for "AT+MS=12,1,34667,56000".
There are examples shown for how 56K can be disabled, or
for how various flavors (V92, V90, K56Flex, X2) can be
tried first.

http://www.digistar.mb.ca/client/56kprobs.htm

My experience with this stuff, is virtually every modem I've
ever used, I've had to spend a week of evenings tuning it
and trying settings. The only modem that was reasonably
trouble free, was actually a Winmodem on a relative's
computer.

So you may get lucky, or you may end up doing a lot of
hard work, to figure out why it won't do 45K.

Paul
 

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