Another 56K question

[Web Gecko]

Howdy

Thanks to GLC I cleared up my last 56K question. OK so if you're running a V.90 56K modem (do you guys in the US get around 43Kbps max ?) and you average around 40 Kbps (In Oz we rarely manage 53/54K initial connect) then your max download rate is around 5Kbytes per second.

OK, so is this upper limit only for ftp or what ? Or are we talking maximum downstream rate for everything period i.e. web pages or any downstream traffic ?

If this is the case then it seems that 56K is a major crock (which it is anyway)
as it looks more like 40K to me. Am I wrong about this ? But then we get our extra 6.4 Kbps over V.34 so we're laughing right ? Or is that someone else I hear laughing (go ahead it's a free universe).

There is also an article under modems (standards) on this site that suggests there is an upper limit on upstream V.90 traffic of 33.6Kbps ? How about this one ?

Thanks

cheers

Web Gecko

p.s. My ISP and Telco are the ones laughing here as my phone line is a dinosaur
pair gains cable (split line) hanging off a dinosaur rim system 12 AXE
exchange.

I get 28.8/31.2 Kbps max so I don't bother with V.90 when my V.34 is
running cool anyways. No cable or ADSL in my area. Satellite and
64K ISDN aren't worth the trouble and expense.

chou

[reboot]

Under ideal conditions (and with no government intervention) one could theoretically get 56kbps.
Now add into the equation the less-than-ideal stuff.
Phone lines. They will only perform at their peak when at absolute zero (any electrical current through a wire), so the warmer (and more or less humid) it is, the slower the connection gets.
Distance. The longer the cable, the slower it gets, fact of life/physics, and you can't rewrite the laws of physics.
Analog to digital (and back) conversions. More than 1, and you're down to 33.6 max.
Just to throw a screw in the works, compression schemes allow for more data to flow than would be "normal". Thus 6 or 7 kBps, when only connected at 45kbps.
Downstream is limited in the US to 53000kbps by law. Not that anyone (hardly) gets near that speed anyhow.
Upstream is limited to 33600kbps. Go ask the chip manufacturers and modem makers why.
The newer V.92 protocall allows for even more compression than V.90, thus (supposedly) faster downloads. It also allows for an upstream rate increase to 48k.
More here (although the article seems to have been hashed by HTML changes, the content is the same) http://www.pcmech.com/showdoc/183/

[Web Gecko]

Thanks mate, for your response and comprehensive answer to my question.
I should have known 56K was going to turn out not that straightforward
(pinnable ?) and is obviously not what it seems or how the sales people explain it (they haven't got a clue usually).

A networking consultant I keep in contact with in Massachusettes(he's generally too busy to answer all my questions) basically told me you need to measure your dynamic line speed directly as it changes. I assume he means there would be something like a line monitor which you could hang off your phone line to do this.

Even though I am on an old split phone line, I have switched to an old P90 system running Win95a and a V.34 internal. I usually get 28.8Kbps and sometimes
31.2Kbps if lucky. I don't know exactly what's going on but things seem to be working much quicker for me (without running Opera 5.12 over IE 5.5 even).

I have a nephew up there in Vernon Alberta who is planning to bring his Canadian fiancee back to Perth to marry in 2002. I also know some people in Winnepeg and Windsor Ontario.

Thanks again

chou

The Web Gecko

[reboot]

Glad it explains it a bit better.
Actually Vernon is in B.C., just about 1/2 an hour from here.

[azscary]

I HOPE THIS HELPS


SUBJECT: Modems: Factors Affecting Speed of 56k Connections

Factors Affecting Speed of 56k Connections

--------------------------------------

There are a number of factors which could be preventing you from getting
higher connection speeds. We will try and cover the most frequently
encountered problems and what you may be able to do to help.

Let's just go over a few of the more obvious reasons why 56K wouldn't be
working.

--------------------------------------
A. Your modem doesn't support either the X2 or V90 protocols. Instead it
supports KFlex.

In this situation, you would need to obtain a V90 upgrade from your
manufacturer. If you are not sure your modem supports V90, this is the
first thing to check. See the links for Drivers/Firmware listed below.

--------------------------------------
B. If your office is on a PBX, you may have problems getting speeds higher
than 28.8 .

Many offices use PBX telephone systems, a sort of electronic receptionist
and switchboard. If your office telephone has its own extension, or if you
must dial a 9 to get an outside line, you are probably on a PBX. PBXs are
also common in hotels. It's likely that most PBX systems will prevent 56K
modems from working by introducing an additional analog-digital conversion.
See below for more information on analog-digital conversions. If you live
in an apartment complex similiar hardware may prevent 56k connections.

--------------------------------------
C. The connection from the phone line to the modem may be too poor for 56
to work.

This is referring to anything else which may be in the line between the
modem and the wall jack. Examples of items you should remove while
troubleshooting: a splitter at the wall jack, a surge protector that the
line goes through, or a fax machine. The modem should be supplied a signal
by a phone cord no greater than 8-10' long, running straight from the modem
directly into the wall jack with nothing else coming between. It is ok to
plug in other devices (a telephone, fax) into the "Phone" jack on the modem.

--------------------------------------
D. Drivers/Firmware

Having made sure none of the above is the problem, the next thing to cover
would be the modem driver & firmware issues. MindSpring uses 3Com modems
which use the USR chipset, supporting both X2 and V90. Naturally you should
have the least difficulty connecting to MindSpring with V90 if you have a
3Com/USR modem. Other vendors rely on modems that use other chipsets. The
other most common chipset manufacturers are Rockwell, Lucent Technology,
Cirrus Logic, and PCTel. While V90 is the standard for 56K connections, all
vendors have not made the same effort to put out quality drivers and
firmware for their modems to make V90 a real working standard. So as a
general rule, if your modem already supports V90 and it is still not
connecting at 56K speeds, it is a good idea to check for upgraded drivers
and firmware. With V90 being such a new technology, some of the most recent
firmware updates have made great improvements. While MindSpring cannot help
you install modem software, we can direct you to where you can obtain these
updates. Here's a few pages on which you will find links to most all modem
vendors firmware and drivers.

http://www.56k.com/links/Firmware_Updates/
http://www.56k.com/links/V90_Upgrades/
http://www.modemhelp.com/links/56K/V90_Upgrades/
http://www.winfiles.com/drivers/modems.html

--------------------------------------
E. Line Quality

Ok, so you've covered all the obvious reasons, your modem is V90 ready and
has the latest and greatest modem software from the manufacturer and you
STILL are not getting 56K. What to check next? Now we at the point where we
you will need to look into the quality of the phone line supplying the
signal to the modem. Does your line support 56K connection speeds? There a
few ways to check this, none of which are 100% accurate.

USR has setup a web page with instructions on how to run a line test. You
can find it here.

http://www.3com.com/56k/need4_56k/linetest.html

This test has one major limitation. It is using a long distance telephone
call to test line quality for what will be a local call when you are
dialing MindSpring. with your modem.

Depending on what kind of modem chipset you have, there are a couple of web
pages you can go to that have information on how to judge noise on the
local telephone circuits.

For USR and Rockwell chipset modems
http://help.ibm.net/helplib/tlcoinfo.html

For PCI LT WinModems
http://www.multiwave.com/support/rig...cilu_howto.htm

You could also call your local phone company and ask them to check your
line for noise. They often will not tell you anything is wrong because
your telephone company only needs to provide voice quality for local phone
lines. This works out to about a 9600k connection!

If it appears you have a problem with excessive noise on the lines you will
need to contact the local telephone company. Ask to open a trouble ticket,
or to speak to a data specialist directly. Here are some tips on what to
ask about.

1. Be ready to advise them that you have Line Noise and/or Low Line Level.
2. Explain to them you are using a modem (do not hide this) and tell
them normal voice communications is fine. If you do not tell them you
are using a modem they will run a "quick" test and say the line is fine.
3. Also ask the phone company to perform a trace from your home to our
equipment (trace the call from your home to our local access number).
4. Have them check the signal strength and quality through each Central
Office. It may take several attempts to correct the problem especially
when line noise is present.

--------------------------------------
F. Multiple A/D Conversions

A/D stands for analog to digital conversion. This refers to the action
taken on the phone signal by the local telephone company switch that routes
your call to MindSpring. When you place a call from your modem to
MindSpring, it is sent to the local telephone company which uses a series
of network switches to eventually get your call routed to our modems. Some
of these switches use older equipment which do not allow for a digital to
digital conversion of the phone signal through a particular switch. In
these situations an analog to digital conversion is the result. There's one
requirement that will prevent some people from using 56K. For 56K to work,
you can have at most one analog-to-digital conversion between your home or
office and the Internet service provider (ISP). If there's more than one,
you can't use 56K, and your connection will be limited to V.34 speeds (a
maximum of 33.6K). If you have a 3Com/USR 56k modem, there is a fairly
reliable method to determine if you have more than 1 A/D conversion, or
other serious impairment on your line. To find out how to do so go here:

http://808hi.com/56k/x2-adconversion.htm

--------------------------------------
G. How to find out for sure if your phone lines support 56K.

This is the only reliable way I know of to test your phone lines: borrow a
known good 56K modem and try it with your phone lines. By "known good 56K
modem," I mean a modem that has connected at speeds higher than 33.6 .

If it's an internal modem, have your friend bring the whole computer to
your house. In fact, it's easier that way, because their computer will
already be configured for the modem. Use your monitor, keyboard, and mouse
so they won't have to cart them over to your house.

If you can only borrow the modem, be sure to get the disks that came with
it so you can install the drivers for that modem. You'll have to install
the modem and drivers. Be sure to select the modem in your dialing software
(such as Windows 95 Dial-Up Networking or Apple's PPP for Open Transport).

Once their modem is at your house, call their ISP. How fast is the
connection? You can also try calling your ISP, if your ISP and your
friend's modem use the same 56K protocol (x2, K56flex, or V.90).

--------------------------------------
H. Resolutions

It may be your modem manufacturer just has not released drivers or firmware
that will allow a 56k connection. We have seen a number of cases where
customers dialing from the same location, same line get 56K speeds when
using 3Com/USR modems but not Rockwell or Lucent modems. As mentioned
above, some of the more recent updates from these vendors have made great
improvements but not all modem manufacturers have been quick to release
drivers based on the latest updates.

Other situations may exist where Dial-Up Networking connections to one
provider can be made at 56K but not to another. This is entirely possible
and in some case may have no resolution. The phone company routes calls
through different switches when you are calling different numbers. It may
be that when calling MindSpring your call is routed through an additional
A/D conversion as described above as opposed to when you call your other ISP.

We hope this has given you a few things to try and consider regarding your
connection.

--------------------------------------

Article Last Update - 9/01/99