how-to block ads
|
tetujin28g
join:2004-02-10
Los Altos, CA
| [Availability] Losing sync every few hours
I am losing sync every few hours. Modem resyncs automatically, and on resync I get different line rates ranging from 4736k to 6016k. I seem to get more drops during the daytime and also get slower line rates during the day. I have tried three different modems and seems to make no difference. Some log info:
Jun 22 14:37:55 user crit kernel: ADSL link down
Jun 22 14:38:10 user crit kernel: ADSL link up, fast, us=768, ds=5088
Jun 22 14:38:44 user crit kernel: ADSL link down
Jun 22 14:38:56 user crit kernel: ADSL link up, fast, us=704, ds=5248
Jun 22 16:21:41 user crit kernel: ADSL link down
Jun 22 16:21:57 user crit kernel: ADSL link up, fast, us=768, ds=4736
Jun 22 16:23:04 user crit kernel: ADSL link down
Jun 22 16:23:16 user crit kernel: ADSL link up, fast, us=672, ds=4768
Jun 22 17:36:03 user crit kernel: ADSL link down
Jun 22 17:36:18 user crit kernel: ADSL link up, fast, us=768, ds=5024
Jun 22 17:38:21 user crit kernel: ADSL link down
Jun 22 17:38:33 user crit kernel: ADSL link up, fast, us=704, ds=5248
Jun 22 22:02:11 user crit kernel: ADSL link down
Jun 22 22:02:26 user crit kernel: ADSL link up, fast, us=672, ds=5280
Jun 22 23:12:56 user crit kernel: ADSL link down
Jun 22 23:13:08 user crit kernel: ADSL link up, fast, us=608, ds=5952
Jun 22 23:40:00 user crit kernel: ADSL link down
Jun 22 23:40:23 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 23 06:07:09 user crit kernel: ADSL link down
Jun 23 06:07:20 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 23 07:33:24 user crit kernel: ADSL link down
Jun 23 07:33:39 user crit kernel: ADSL link up, fast, us=672, ds=5280
Jun 23 08:10:55 user crit kernel: ADSL link down
Jun 23 08:11:07 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 23 08:12:52 user crit kernel: ADSL link down
Jun 23 08:13:08 user crit kernel: ADSL link up, fast, us=704, ds=5248
Jun 23 08:18:15 user crit kernel: ADSL link down
Jun 23 08:18:27 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 23 11:13:27 user crit kernel: ADSL link down
Jun 23 11:13:42 user crit kernel: ADSL link up, fast, us=640, ds=5376
Jun 23 11:14:27 user crit kernel: ADSL link down
Jun 23 11:14:39 user crit kernel: ADSL link up, fast, us=352, ds=4928
1) Which AT&T DSL Package do you have –
Elite (6.0Mbps down)
2) Which modem brand and model do you have?
D-Link DSL-2640B, Motorola 2210, Speadstream 5660
3) Are you using a router? If so, provide the brand and model.
Linksys WRT54G
4) Is your PPPoE login info (username & password) entered in the modem, in your router or do you use PPPoE software?
In the Modem
5) Describe the lights on the modem when the trouble occurs.
DSL light goes off, Internet light goes off
6) Confirm that you’ve checked to ensure that ALL devices plugged into the wall jacks serviced by your DSL phone number (except the DSL modem) have filters fitted.
Yes all filtered
7) Confirm that you’ve powered off the modem and started it again and whether or not that made any changes with your problem.
Yes, many times
8) Do you hear any type of noise on the DSL phone line or any other unusual telephone symptoms?
No
9) Provide line stats as follows…
ADSL Statistics
Mode: G.DMT
Type: Fast
Line Coding: Trellis On
Status: No Defect
Link Power State: L0
Downstream Upstream
SNR Margin (dB): 6.3 7.0
Attenuation (dB): 25.0 10.5
Output Power (dBm): 15.7 11.9
Attainable Rate (Kbps): 4960 468
Rate (Kbps): 4928 352
K (number of bytes in DMT frame): 155 12
R (number of check bytes in RS code word): 0 0
S (RS code word size in DMT frame): 1 1
D (interleaver depth): 0 0
Delay (msec): 0 0
Super Frames: 230571 230569
Super Frame Errors: 26551 0
RS Words: 0 0
RS Correctable Errors: 0 0
RS Uncorrectable Errors: 0 N/A
HEC Errors: 25840 0
OCD Errors: 51 0
LCD Errors: 0 0
Total Cells: 44751294 0
Data Cells: 766209 0
Bit Errors: 0 0
Total ES: 1426 0
Total SES: 662 0
Total UAS: 168 0 | |
NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
 ·Pacific Bell - SBC
| Your attenuation says you should be good for Elite (6016 kb/s down), but your SNR is marginal, and your attainable rate (same as Max Rate?) is less than the 8000 kb/s you should see to hold synch at 6016 kb/s.
Suggest that you post in the AT&T Direct forum. Seems like there are line issues that need to be addressed.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum | |
pfong
join:2009-06-08
Sacramento, CA
| reply to tetujin28g
If you request to be put on interleave, your SN Margin will rise and connection stability will be quite good. Interleave levels 1 & 2 has very little increased latency, in my opinion, but non-the-less if your into lag-free gaming & voip, then I don't know.. check if it's inside or outside wiring, if it's outside might call AT&T tech, if inside, fix it yourself, eg home-run. you may also have some bridge taps, they removed one from my outside line a few weeks ago. | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to tetujin28g
Re: Losing sync every few hours
Two technicians have come out to work on this and it is still NOT solved. Now it has been referred to the cable maintenance group.
The SNR during the day falls to 6/6 (down/up) but in the late evening hours it sometimes goes up to 13/18 and I get good speeds (> 5mbps), but it doesn't last to the next day. I still get disconnects throughout the day and speeds are around 3 to 4 mbps.
Is the problem due to higher traffic during the day or higher temperatures?
I will call ATT Monday to check on the status with the cable maintenance people. | |
NormanS
Premium,MVM
join:2001-02-14
San Jose, CA
·Pacific Bell - SBC
| S/N ratio is a measure of the ratio of usable signal to noise. Too low, and the modem can't differentiate the signal from the noise. It is an electrical characteristic, which should be reasonably stable, barring certain systemic changes (I don't think traffic volume qualifies as the kind of systemic change that would greatly affect S/N ratio).
If your neighborhood has Uverse available, the F2 span should have been conditioned for Uverse. If the problem isn't in the F2 span, it could be in the F1 span, which doesn't need to be conditioned for Uverse. I think it could also be a problem with the DSLAM; but, if they have cable maintenance on it, they probably already ruled out issues at the DSLAM.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to tetujin28g
Re: [Availability] Losing sync every few hours
Yes, I know what S/N ratio is. The questionn is why it varies from a low of 6.1 during the day to a high of 12.9 at late night.
Right now (9AM Sunday) it's:
SNR Margin (dB): 6.1 6.0
Attenuation (dB): 24.0 11.0
It was this last night around midnight:
SNR Margin (dB): 12.9 19
Attenuation (dB): 22.0 10.0 | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to tetujin28g
This morning I have:
Downstream Upstream
SNR Margin (dB): 16.4 19.0
Attenuation (dB): 18.0 9.0
Output Power (dBm): 12.3 11.9
Attainable Rate (Kbps): 9952 1248
Rate (Kbps): 6016 768
which is excellent. How long will this last?
A few hours ago things were very unstable (sync down and up 14 times in 1 hour!):
Jun 30 00:39:58 user crit kernel: ADSL link down
Jun 30 00:40:13 user crit kernel: ADSL link up, fast, us=608, ds=6016
Jun 30 00:40:48 user crit kernel: ADSL link down
Jun 30 00:41:00 user crit kernel: ADSL link up, fast, us=704, ds=6016
Jun 30 00:43:54 user crit kernel: ADSL link down
Jun 30 00:44:09 user crit kernel: ADSL link up, fast, us=704, ds=6016
Jun 30 01:00:10 user crit kernel: ADSL link down
Jun 30 01:00:22 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 30 01:01:04 user crit kernel: ADSL link down
Jun 30 01:01:19 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 30 01:01:51 user crit kernel: ADSL link down
Jun 30 01:02:03 user crit kernel: ADSL link up, fast, us=672, ds=6016
Jun 30 01:02:31 user crit kernel: ADSL link down
Jun 30 01:02:46 user crit kernel: ADSL link up, fast, us=576, ds=6016
Jun 30 01:03:17 user crit kernel: ADSL link down
Jun 30 01:03:29 user crit kernel: ADSL link up, fast, us=640, ds=6016
Jun 30 01:05:56 user crit kernel: ADSL link down
Jun 30 01:06:11 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 30 01:07:33 user crit kernel: ADSL link down
Jun 30 01:07:45 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 30 01:08:16 user crit kernel: ADSL link down
Jun 30 01:08:31 user crit kernel: ADSL link up, fast, us=768, ds=6016
Jun 30 01:09:01 user crit kernel: ADSL link down
Jun 30 01:09:13 user crit kernel: ADSL link up, fast, us=704, ds=6016
Jun 30 01:36:06 user crit kernel: ADSL link down
Jun 30 01:36:21 user crit kernel: ADSL link up, fast, us=736, ds=6016
Jun 30 01:37:13 user crit kernel: ADSL link down
Jun 30 01:37:25 user crit kernel: ADSL link up, fast, us=768, ds=6016 | |
StillLearn
Premium
join:2002-03-21
Streamwood, IL
·AT&T Midwest
| reply to tetujin28g
Re: [Availability] Losing sync every few hours
I agree that they have implied that the problem is suspected away from your house, since they have passed this on to the cable maintenance people. Still, it would not hurt to look for local sources of noise. See »Ameritech - SBC FAQ »My DSL loses sync regularly. How can I detect interference with an AM Radio? | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to tetujin28g
Now at 7:20 AM:
Downstream Upstream
SNR Margin (dB): 6.1 6.0
Attenuation (dB): 19.0 10.0
Output Power (dBm): 15.7 11.9
Attainable Rate (Kbps): 5856 784
Rate (Kbps): 5824 672
Bad already! | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to StillLearn
Yesterday an ATT tech guy (the 4th one) came out and checked the lines from the RT to B-Box and to my house and he said they all were good. I had him check the SNR Margin at the B-Box and it was 7.5db (not good). He then swapped some stuff (not sure what) and things got a little better but as my prior post says, it's still not fixed.
It seems to me something is putting noise on my line from around 7AM to around midnight.
I have tested my connection with all inside wiring removed (modem straight into the jack at the NID) and I still have the same noise problem. | |
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
1 edit | reply to tetujin28g
If you post a good and a bad period DMT chart from the 2210, then maybe a comparison will show if certain frequencies are impaired by interference: »SBC DSL FAQ »How can I check for the maximum attainable sync speeds with a 5100b/4100 modem? This comparison can help locate the source of in-residence interferences or sometimes suggest if the source is due to problems on AT&T's lines.
If there is no apparent RFI interference in the DMT charts, then the interference might be due to impulse noise source only which you may be able to locate. | |
tetujin28g
join:2004-02-10
Los Altos, CA | reply to tetujin28g
I unfortunately sold my 2200 modem. I am using D-Link 2640B right now. I don't see a way to get DMT charts from it. Anyone know if there is a way? | |
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| reply to tetujin28g
The DMT tool wouldn't work with the D-Link now.
First, the modem would have be able to output a raw tone bin table. Then the tool would have to be revised by deblin  to be able to parse that data. | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to tetujin28g
The latest with me and ATT: The 4th tech, the one from digital cable maintainance, couldn't find anything wrong with the line from the RT to the B-box. I asked about the line from the B-box to my house and he said that's another cable maintaince group's responsibility. What? Then a little later I hear the doorbell and it's him. His dispatcher told him to measure the line quality at my house -- kudos to the dispatcher. He measured the stress of the line from my house to the B-box as well as the wiring inside my house. Both turned out to be normal.
I asked him to measure the SNR margin back at the B-box and it was 7.5db for the downstream. He swapped some things and then called me and said the SNR is now 10db at the B-box. But I still see only 6db at my modem.
That was yesterday. Today I called to see what's happening and the service rep offered to have the card at the RT changed. "OK" I said, but why did they not think of this before?
To be contuned. | |
tetujin28g
join:2004-02-10
Los Altos, CA
1 edit | Well the card replacement has yet to happen. Yesterday the card was only tested (and it tested bad), but no action to replace it had been initiated until I called. So it was supposed to get replace today. But no, nothing has happened, and I called again and the replacement had to be reordered for tomorrow.
Overall my confidence that ATT Customer Service can solve issues is now very low. | |
tetujin28g
join:2004-02-10
Los Altos, CA
1 edit | reply to tetujin28g
The saga continues:
I have been trying to get a problem with my poor DSL connection resolved for over a week with still no resolution. 4 field techs have come out and inspected the cables from the RT to the B-box and to my house, swapped lines, ran tests, etc. and my connection is still unstable. Each field tech concluded that it was not his problem and passed the problem on to another group. After the fourth field tech coudn't solve the problem (he even tried to deny there was a problem) the trouble ticket got closed prematurely. Two days ago I called for status and the support person on the phone said they needed to replace the card in the RT and opened a new trouble ticket and ordered a replacement. If i hadn't called, would anything have happened? Yesterday when I checked on the status I was told no replacement has been done and the card was only tested to see if it was bad, which it was. A replacement was then really ordered for today. Then today I called for the status and nothing had been done! They reordered the card replacement and someone will be dispatched tomorrow to perform the replacement.
I find a severe lack of coordination between the different groups tasked to solve my problem. Groups such as Network Services and Cable Maintenance only look at their part and hand the problem off to someone else, and focus on the problem gets lost. There is no single individual in who owns the problem within ATT Customer Support. Trouble tickets are closed prematurely and communications between groups get lost and things like card replacements don't get done. I have called ATT Boradband support everyday this week to revive action on my problem, which seems to get neglected if I do not call.
This is no way to run a customer service organization.
Also, the 877-722-3755 support number is useless and should be removed. The 888-720-1275 is much more effective. The people on this support line are knowledgeable and caring. But they must rely on different specialized groups in ATT to get things done, and each group has only a very narrow perspective of the problem. A more integrated customer service process is needed, where there is a single problem owner who has broad knowledge of the issues of DSL and who can coordinate the activites of the various specialist groups. | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to tetujin28g
Well no one showed up on Friday. Being the day before 4th of July, I called ATT just to make sure someone was going to come out that day. I was assured that a field tech would be dispatched before 8PM, even if it was the day before 7/4 and most people have the day off. But as I said, no one came out! I called tonight (Sun) to see what was going to happen. The agent acknowledged that the Friday promise was broken. He couldn't tell me why. Grrrrr... Seems like another case where one part of ATT does not know what the other part of ATT is doing. Is there an internal political problem?
I now have a person coming tomorrow (Mon) morning. What is strange is that the agent told me I should have never been told about an RT card replacement, despite three prior calls where the agents discussed card replacement with me. Is the field tech coming tomorrow going to start from the beginning again and point the finger to someone else?
BTW, I have started to get quotes on cable internet service..... | |
tetujin28g
join:2004-02-10
Los Altos, CA
| reply to tetujin28g
The End:
It's been a week since last posted. Since then, 5 field techs have come out.
Monday: field tech says I'm too far from the CO. Well I'm on a RT, only 3000 feet away. He doesn't buy it.
Tuesday: after calling St. Louis I have the same field tech come out again. He calls me and says he already came out on Monday and there is no point of him coming out again. His manger calls me and I explain that the distance from the CO is not the issue. He gets the field tech to come out again, during the Michael Jackson memorial. After the memorial the field tech says he's done with what he can do. I say it's still not fixed and ask him to refer the problem to someone else.
Wednesday: another field tech comes out. Says confidently the problem is either in the RT or in the line between the CO and RT. Refers the problem to the Pair Gain group.
Thursday: nothing happnes.
Friday: field tech from the Pair Gain group checks the lines and says they are OK. Refers problem back to INR. Later an INR field tech comes out saying he got dispatched to fix a "no dial tone" problem on my line. I tell him I have no dial time problems. He thought so, too, and gives me the number of his manager. I call the manager, a very good guy to deal with, and he says Pair Gain is coming out again on Sat.
Sat: Pair Gain guy reroutes me from the CO to RT. Things are a little better (less disconnects, but still the nosie margin is 6db and I get a couple of disconnects on Sunday).
Sunday: couple of disconnects, and noise margin is 6db or less.
Monday: I call the field manager and he sends his DSL "Go To" guy out. This guys is SUPER! He tests my line, says there is a definite problem. He's using equipment I have not seen before. I see him climbing the telephone pole in front of my house. This guy is on to something. After over two hours of work he has me up and running on a super clean line!!!
Downstream Upstream
SNR Margin (dB): 13.6 18.0
Attenuation (dB): 19.0 9.5
Output Power (dBm): 15.8 11.9
Attainable Rate (Kbps): 8224 1224
Rate (Kbps): 6016 768
BRAVO!
The field tech says the problem was hard to detect, and he can see why the earlier field techs missed it.
I call the field manger to thank him, and he said that his "Go To" guy was in training last week and regrets he couldn't come out to deal with my problem sooner.
Moral of story: keep pushing to get the service you signed up for. Don't take "you're too far" as an explanation for poor performance. | |
drjim
Premium,MVM
join:2000-06-13
Torrance, CA
clubs: | Glad you got it fixed! | |
-
|
