As I am sure you know we support both the k56Flex and the v.90 technology.
There are severall key factors that need to be met to allow k56 technology to work. If these conditions are not met, it is very unlikely that k56 technology will work for you. I repeat very unlikely, "not impossible"...
The newest barrier to 56k performance is the presence of a SLC96 (pronounced
"slick")
concentrator. These are used by phone companies to split up existing
phone hubs to get more
numbers in high growth areas. The split nullifies the k56 capability,
dropping all lines to
v.34 specifications. A second and similar reason is split phone lines
within your home or
office. This usually occurs when you add a new line and the telco instead
of running a new
line, splits the existing one.
There are no specifications showing just how many customers are connected
to SLC96
concentrators, some modem manufacturers estimate between 10-15%.
Another problem occurs when a phone line is stretched beyond 3 miles. You
must be within 3
miles of your Central Switching Station (where all of your home calls are
routed by the phone
company). Call your operator and ask where your Central Switching Station
is. Two conditions
here apply, the phone line can be no longer than 3 miles for the k56 technology
to work. If
you live 3 miles from the Central Switching Station, but your phone line
doesn't go in a strait
line and its is over 3 miles, it is unlikely to work. For some reason the
effective range of
k56 is 3 miles. You can drive to the location the operator gave you, on
your way home watch
the odometer. If it is less than three miles that is good.
Corporate office users lose capability if they are on a PBX switch,
this introduces line
attenuation. You must consistently connect at or above 26400.
At the Central Switching Station there must be a Digital Trunk routing
the calls.
Another factor that we have found to be important, Firmware. Firmware is
what is programed
into the chips. Your version of firmware must be above 1.0.x to be compatible
with k56
Terminal Servers. Whether it is at I-Link International, Inc. or any other
ISP, your firmware must be above
1.0.x or you will not connect at k56 Flex speeds.
If you will notice, all of the above conditions that are necessary to make
k56 work
effectively are controlled by the phone company, not by I-Link International,
Inc. or any other Internet
Service Provider. These are some of the main reasons why k56 is still in
beta testing,
because all of the necessary factors to make k56 work are controlled by
the phone company.
K56 technology is being tested and improved upon almost daily. When
modern manufacturers
release the modems on the market they come with a specific Firmware version.
When they make
improvements to a better Firmware version, not all modems will be specifically
backwards
compatible. It is for this reason that you must check your firmware version.
Even if you
bought your modem yesterday, there's no telling how long the modem sat
in the store, so you
want to check the firmware version.
To check your modem's Firmware version you must get to terminal mode
and
type ATI3. To upgrade the Firmware call the manufacturer of your modem.
They will either send you a disk,
or tell you where online you can download the new firmware. If you are
unfamiliar with this
it is recommended that you do not attempt it. You could very successfully
delete the firmware
on the modem and it will never work again. They will also help you install
it. Not all modems
can be upgraded, it is because of this that some manufacturers will just
ask that you send the
modem back to them, and they will send you an upgraded modem.
It is also important to note that many dial up programs, especially
Windows 95 Dial Up
networking, have a "Connected At" screen. This program does not
tell you that actual
connection speed, nor does it tell you the Data Transfer rate. In other
words, if it says
"You are connected at 31200Kbps" and you are using a perfectly
functioning k56 Flex compatible
modem this does not mean you are connected at and transferring data at
31200Kbps. This number
is simply the Line read at the instant you connected. You should also keep
in mind that k56
Flex technology only works in one direction, downloading. You will only
get the increase in
speed in the downloading, your uploading will default to 28.8 or 33.6 depending
on your modems
default.
Some bad news!
Anything that adds to the line noise on telephone lines causes an analog
to digital
conversion between your ISP and your modem lessens the transmissions performance.
The worse news!
If there's nasty noise on your phone line, your only solution may
be to move.
Scream all you want, but the telco company is currently obligated only
to provide you with
a clean enough line to get 4,800bps data rates. This is no where near the
modems speeds of
today 28,800bps, and 33,600bps.
Both 56k specifications used today take advantage of nuances in the way
the phone system is
designed. In a standard call between two modems, your data must be translated
into analog
"tones" the it can be transmitted across the telephone network.
This translation is called
the digital-to-analog conversion. Once your data reaches a telephone company's
central office,
it's translated back to digital form by a coder/decoder (codec) for transmission
across the
phone company's digital backbone. Unfortunately, because the telephone
network contains some
random noise, the analog-to-digital conversion is only an approximation
of the original
digital signal. To ensure that your data remains readable despite the effects
of this
quantization noise, transmission rates are currently limited to about 35
kbps.
However, because most Internet service providers connect directly to
the phone company's
digital backbone using routers, data coming from an ISP need never undergo
an analog-to-digital
conversion. Instead, the data can be encoded (using pulse code modulation,
or PCM) so that it
remains entirely digital until it gets to the central office. Once it arrives,
the data is put
through a digital-to-analog conversion before being sent across the analog
phone lines to your
modem. And since digital-to-analog conversions aren't affected by quantization
noise, the
result in theory, at least--is throughput as high as 56 kbps from your
ISP to you.
I hope this will clear up a few of your questions, and/or assist
you in solving
any of your problems.