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timoch
Tl Posts:
16

Posted - 12/24/2001 12:34:31 PM  Show Profile  Email Poster  Edit Message
I have a Dell 350 mhz with a USR Sportster internal voice modem flashed to V90. I usually log on at 45333, but, periodically I get cut off. From Hyperterminal I find that the reason is "unable to retrain". Does this problem originate from my modem, the phone line, or from my ISP? The following is the Hyperterterminal log. Thanks.
ati6i7i11y11
U.S. Robotics 56K Voice INT Link Diagnostics...

Chars sent 1438367 Chars Received 9122606
Chars lost 0
Octets sent 680008 Octets Received 7165164
Blocks sent 25940 Blocks Received 60929
Blocks resent 0

Retrains Requested 0 Retrains Granted 0
Line Reversals 0 Blers 0
Link Timeouts 0 Link Naks 0

Data Compression V42BIS 2048/32
Equalization Long
Fallback Enabled
Protocol LAPM
Speed 45333/21600
V.90 Peak Speed 45333
Last Call 02:13:45

Disconnect Reason is Unable to Retrain

Configuration Profile...

Product type US/Canada Internal
Product ID: 00178500
Options V32bis,V.34+,x2,V.90
Fax Options Class 1/Class 2.0
Line Options Caller ID, Distinctive Ring
Voice Options Speakerphone, TAD
Clock Freq 92.0Mhz
EPROM 256k
RAM 32k

FLASH date 2/24/98
FLASH rev 4.9.1

DSP date 2/24/98
DSP rev 4.9.1

U.S. Robotics 56K Voice INT Link Diagnostics...


Modulation V.90
Carrier Freq (Hz) None/1920
Symbol Rate 8000/3200
Trellis Code None/64S-4D
Nonlinear Encoding None/ON
Precoding None/ON
Shaping ON/ON
Preemphasis (-dB) 5/8
Recv/Xmit Level (-dBm) 17/9
Near Echo Loss (dB) 5
Far Echo Loss (dB) 0
Carrier Offset (Hz) NONE
Round Trip Delay (msec) 4
Timing Offset (ppm) -3593
SNR (dB) 45.8
Speed Shifts Up/Down 0/0
Status : uu,5,12N,12.2,-0,1N,0,43.9,27.2

Freq Level (dB)

150 23
300 17
300 17
600 17
750 17
900 18
1050 18
1200 19
1350 19
1500 20
1650 20
1800 21
1950 21
2100 22
2250 22
2400 23
2550 23
2700 24
2850 24
3000 24
3150 25
3300 25
3450 26
3600 29
3750 32
OK

Bob Starnes
Tl Posts:
4360

USA
Posted - 12/24/2001 9:50:11 PM  Show Profile  Email Poster  Edit Message
Retrains are most often caused by noise on the phone line that causes the modem to lose the carrier, when the carrier is lost the modem attempts to recover it by retraining (renegotiating the connection, just like connecting for the first time), but if the noise on the line is too severe and/or last too long then the modem is "unable to retrain".

Don't see any indication of a retrain request in the Link Diagnostics, doesn't even show any speed shifts. Line quality and S/N Ratio look very good. Also not showing any Blers, Timeouts or Link NAKS.

Very strange...

-Any- noise on your phone line, possibly something intermittant? Might pick up the phone and listen without a dialtone immediately after the disconnect to see if you hear anything.

Might try removing all phones and phone line devices from the same line that the modem is on and try a connection with just the modem using the line. Some phone and answering machines have been known to interfere with modems.

Could also try the modem on a known good line to see if the same problem occurs, if not then look to the phone line for the cause, if so the the modem may be suspect.

timoch
Tl Posts:
16

Posted - 12/25/2001 8:06:22 PM  Show Profile  Email Poster  Edit Message
Usually, when talking extended periods on the phone, I don't hear extraneous noises nor do I when
I dial a single digit to clear the dial tone. One thing my son found when he was visiting us, was quite a bit of RF hum that he picked up with his portable ham radio, originating from a flakey splice on the same utility pole that carries the phone and cable lines. This causes some snow on the lower channels on the cable. The hum seems to be intermittent. A friend who works at the power company looked at the splice, but so far the Co has repaired it. Could that be the problem?
Another thing, the hang ups seem to be much more frequent during the day than late at night
timoch
Tl Posts:
16

Posted - 12/25/2001 8:07:15 PM  Show Profile  Email Poster  Edit Message
Usually, when talking extended periods on the phone, I don't hear extraneous noises nor do I when
I dial a single digit to clear the dial tone. One thing my son found when he was visiting us, was quite a bit of RF hum that he picked up with his portable ham radio, originating from a flakey splice on the same utility pole that carries the phone and cable lines. This causes some snow on the lower channels on the cable. The hum seems to be intermittent. A friend who works at the power company looked at the splice, but so far the Co has repaired it. Could that be the problem?
Another thing, the hang ups seem to be much more frequent during the day than late at night
Bob Starnes
Tl Posts:
4360

USA
Posted - 12/25/2001 8:44:37 PM  Show Profile  Email Poster  Edit Message
Could very well be part of the problem but something like a bad power line causing static would more likely just cause low speeds connects if it's coming through the phone line. I'd think there'd have to be a good bit of audible noise on the line to cause the modem to not be able to regain the carrier.

Don't know if I'm missing something obvious but given all the good numbers in the Link Diagnostics and the lack of errors, speed shifts and retrains, the "Unable to Retrain" is most puzzling. Perhaps someone else could offer an opinion.

v.Richard
Tl Posts:
6222

USA
Posted - 12/26/2001 8:31:12 AM  Show Profile  Email Poster  Edit Message  v.Richards Homepage
Unable to retrain - when the diagnostics don't show any retrains requested/granted is unusual.

Your modem with non-standard init string, or your ISP's modem can be set to disallow retrains (ie, disconnect if a retrain would otherwise be required).

You can test your init string by adding a custom string of &F1
www.modemsite.com/56k/initmagic.htm

I'd also note the low upstream rate (21.6k) and high downstream (peak over 50k); you might do better by limiting your connect speed - try 48k
www.modemsite.com/56k/x2-linklimit.htm

Aloha,
Richard

timoch
Tl Posts:
16

Posted - 12/26/2001 7:38:36 PM  Show Profile  Email Poster  Edit Message
Actually I wish I could try 48k. My upper limit is set for 45333, and it always logs on at that speed. If I leave the extra settings box blank, about 30% of the time it logs on at 49333k then it seems to be a lot slower than at 49333. During the day, the dial up sometimes takes 5-6 tries, late at night it often makes it on the first try....
When I was using IE 5.5 I not only had the disconnect problems, but the browser seemed to fall asleep and I would have to refresh to be able to connect to the next link. I got Opera 5.12, and the latter problem went away. Now I have Opera 6.0, and it sometimes requires hitting the "go" button a couple of times to get it going.
timoch
Tl Posts:
16

Posted - 12/26/2001 7:45:43 PM  Show Profile  Email Poster  Edit Message
The above diagnostics was made immediately after a disconnect. One thing that I noticed on other diagnostics that I have taken after other disconnects is that the SNR is very high, over 4700, with one retrain granted and none requested. I seldom have more than a couple bliers per session: maybe that will help.
timoch
Tl Posts:
16

Posted - 12/28/2001 5:17:55 AM  Show Profile  Email Poster  Edit Message
Here is some additional info about the disconnection. The log on CiDial (a software redialer) when a DC occurrs reads, "error 6 hangup ras hangup". This morning I've had two DC's within 30 minutes. Here is the Hyperterm reading for the last one. I had logged on at 45333. I would appreciate any advice that you could offer.

ati6i7i11y11
U.S. Robotics 56K Voice INT Link Diagnostics...

Chars sent 322724 Chars Received 1227057
Chars lost 0
Octets sent 168019 Octets Received 878580
Blocks sent 4184 Blocks Received 7817
Blocks resent 4

Retrains Requested 3 Retrains Granted 0
Line Reversals 0 Blers 2
Link Timeouts 0 Link Naks 1

Data Compression V42BIS 2048/32
Equalization Long
Fallback Enabled
Protocol LAPM
Speed 12001200
Last Call 00:16:08

Disconnect Reason is Unable to Retrain

Configuration Profile...

Product type US/Canada Internal
Product ID: 00178500
Options V32bis,V.34+,x2,V.90
Fax Options Class 1/Class 2.0
Line Options Caller ID, Distinctive Ring
Voice Options Speakerphone, TAD
Clock Freq 92.0Mhz
EPROM 256k
RAM 32k

FLASH date 2/24/98
FLASH rev 4.9.1

DSP date 2/24/98
DSP rev 4.9.1

U.S. Robotics 56K Voice INT Link Diagnostics...


Modulation V.22
Carrier Freq (Hz) 1829/1920
Symbol Rate 3200/3200
Trellis Code 64S-4D/64S-4D
Nonlinear Encoding ON/ON
Precoding OFF/ON
Shaping ON/ON
Preemphasis (-dB) 2/8
Recv/Xmit Level (-dBm) 16/9
Near Echo Loss (dB) 5
Far Echo Loss (dB) 71
Carrier Offset (Hz) -2016
Round Trip Delay (msec) 4
Timing Offset (ppm) -3591
SNR (dB) 11704
Speed Shifts Up/Down 0/0
Status :


Freq Level (dB)

150 23
300 17
450 17
600 17
750 17
900 18
1050 18
1200 19
1350 19
1500 20
1650 20
1800 21
1950 21
2100 22
2250 22
2400 23
2550 23
2700 24
2850 24
3000 24
3150 25
3300 25
3450 26
3600 29
3750 32

Bob Starnes
Tl Posts:
4360

USA
Posted - 12/28/2001 2:05:58 PM  Show Profile  Email Poster  Edit Message
Something must have gotten pretty bad:

> Speed 12001200

> Modulation V.22

Connect speed down to V.22/1200bps at the time of disconnect.

Take your computer to another location and try a connection to your ISP using a known good phone line, see if you can get a better, more stable connection. If so then there's something on your phone line causing the problem, if the problem still exist using a different phone line then the modem may be about to go south.

v.Richard
Tl Posts:
6222

USA
Posted - 12/31/2001 12:29:08 PM  Show Profile  Email Poster  Edit Message  v.Richards Homepage
You might also try connecting modem directly to your phone line demarc or removing all other devices -
www.modemsite.com/56k/demarc.htm

As Bob says, that last diag indicates something really bad - and iot may be your modem.... (although it could be your ISPs modem or the combination....)

Aloha,
Richard

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