Re: Sloooooo Modem

Josh Hillman ( (no email) )
Fri, 30 Jan 1998 11:29:59 -0500

> From: Ed Miller <emiller@del.net>
> Just signed up a customer yesterday the has a "Standard" 14400 modem.
> He tells me that he was signing on at 14400 with his last carrier but
gets
> 1200 with us. I looked at the output of the "modemdiag" from the Max
4000
> running +5.0Ap33 software and got this, I think.
>
> TERMINATION REASON.......... 3 RETRAINS
> LAST TX rate................ 28800 BPS
> HIGHEST TX rate............. 28800 BPS
> LAST RX rate................ 300 BPS
> HIGHEST RX rate............. 300 BPS
> PROTOCOL.................... LAPM
> COMPRESSION................. V42Bis
> Line QUALITY................ 127
> Rx LEVEL.................... 047
> Highest Rx State............ 00
> Highest TX State............ 00
> EQM Sum..................... 0000
> RBS Pattern................. FF
> Rate Drop................... FF
> Local Rtrn Count............ 01
> Remote Rtrn Count........... 00
> V8bis K56Flex not successful

If you/he have no idea what the modem actually is (brand/model), choose
Standard 28800 in the case above (since it's a 28.8 and not a 14.4). I
don't recall if choosing "Standard 28800" does this or not, but if I
remember correctly, choosing "Standard 14400" prevents the use of Error
Control and Data Compression. The lack of error control can play a huge
role in the reliability of the connection. Notice that the
Ascend-Disconnect-Cause was either 11 or 185 in the above case. The reason
was because of the retrains. Those retrains popped up more than likely
because of too many variations in line quality.

We have a user that displays almost identical "modemdiag" results after the
connection ends, though the disconnect cause is always a "normal" 45 or 31.
The user's uploading speed (LAST RX rate and HIGHEST RX rate (these
values/names are relative to the Max)) always display 300bps and yet the
the Ascend-Data-Rate (user's upload speed) displays "9600". I don't
remember what the user's download speed normally is, but it's a normal
number like 28800, 26400, 21600 or if it was a 14.4 modem, then 14400...

I've only seen this behavior with a couple users, and it's always the same
people. I'm guessing it's some kind of quirk with the interaction of their
modems (probably generic junk) and the Maxes.

According to Ascend Support, the lower the line quality value, the better.
But again, as in the example you posted, our similar few users display 127
also, which is far higher than the normal 20-30 something. I'm guessing
that the 127 isn't a valid number (like 28 or something) and represents
something else--afterall, it's always this number for these people and it's
also a nice "digital" number in a series starting with 0...

Josh Hillman
hillman@talstar.com