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View Full Version : OT: Any ADSL gurus? I need help.



jacampb2
04-07-2009, 09:16 PM
For the last few months my DSL modem has been loosing sync with the broadband/internet connection. I have had this same service for 7 years, no issues like this before. Last year I upgraded to the 6mbs service, but as I said, this crap has only been happening for the last few months. The modem is a 2wire modem, the same that I got when I initially signed up for the service...

Bellow is less than an hour of the modems log, as you can see, sometimes it looses signal every few minutes. I have tried rebooting the modem w/ no luck. It is driving me absolutely ape****. I think this is the log that shows what is happening. For the money I spend, this is ridiculous. My signal strength is pretty good, I think is said 6dB noise downstream and 13dB upstream, from all I have read this is good to great. I am physically located less than 2 miles from the switch... If anyone knows why this is going on, please let me know.


INF 2009/04/06 14:25:51 EDT adsl: Margin:6.0/14.0 Atten:36.2/23.0 Power:19.0/11.9
INF 2009/04/06 14:25:51 EDT adsl: Country: {F} Vendor: {ALCB} Specific: {0}
WRN 2009/04/06 14:28:27 EDT adsl: adsl connection lost due to errored seconds limit
INF 2009/04/06 14:28:27 EDT adsl: adsl0: down (signal lost)
INF 2009/04/06 14:28:47 EDT adsl: adsl0: up G.DMT fast Rate:6016/768 Max:6720/1024
INF 2009/04/06 14:28:47 EDT adsl: Margin:6.0/14.0 Atten:36.2/23.0 Power:19.4/11.9
INF 2009/04/06 14:28:47 EDT adsl: Country: {F} Vendor: {ALCB} Specific: {0}
WRN 2009/04/06 14:30:24 EDT adsl: adsl connection lost due to errored seconds limit
INF 2009/04/06 14:30:24 EDT adsl: adsl0: down (signal lost)
INF 2009/04/06 14:30:44 EDT adsl: adsl0: up G.DMT fast Rate:6016/768 Max:6752/1024
INF 2009/04/06 14:30:44 EDT adsl: Margin:6.0/13.0 Atten:36.2/23.0 Power:19.1/11.9
INF 2009/04/06 14:30:44 EDT adsl: Country: {F} Vendor: {ALCB} Specific: {0}
WRN 2009/04/06 14:32:05 EDT adsl: adsl connection lost due to errored seconds limit
INF 2009/04/06 14:32:05 EDT adsl: adsl0: down (signal lost)
INF 2009/04/06 14:32:25 EDT adsl: adsl0: up G.DMT fast Rate:6016/768 Max:6752/1024
INF 2009/04/06 14:32:25 EDT adsl: Margin:6.0/14.0 Atten:36.2/23.0 Power:19.2/11.9
INF 2009/04/06 14:32:25 EDT adsl: Country: {F} Vendor: {ALCB} Specific: {0}
WRN 2009/04/06 14:36:08 EDT adsl: adsl connection lost due to errored seconds limit
INF 2009/04/06 14:36:08 EDT adsl: adsl0: down (signal lost)
INF 2009/04/06 14:36:27 EDT adsl: adsl0: up G.DMT fast Rate:6016/768 Max:6752/1028
INF 2009/04/06 14:36:27 EDT adsl: Margin:6.0/14.0 Atten:36.2/23.0 Power:19.1/11.9
INF 2009/04/06 14:36:27 EDT adsl: Country: {F} Vendor: {ALCB} Specific: {0}
WRN 2009/04/06 14:48:44 EDT adsl: adsl connection lost due to errored seconds limit
INF 2009/04/06 14:48:44 EDT adsl: adsl0: down (signal lost)
INF 2009/04/06 14:49:03 EDT adsl: adsl0: up G.DMT fast Rate:6016/768 Max:6816/1024
INF 2009/04/06 14:49:03 EDT adsl: Margin:7.0/14.0 Atten:36.2/23.0 Power:19.5/11.9

I have 2 days of log showing the same thing over and over, 22 signal losses in the last two days, total of 6.5 hours of signal lost over the last 12 days, all it 10-20 second intervals. lovely, huh?

Thanks,
Jason

2ManyHobbies
04-07-2009, 10:56 PM
Might be a 7+ year old modem, or the caps therein. Not sure if that message means you are losing sync or something like PPP is dropping instead.

Call the helpdesk and see if they can pull stats on the line of device upstream. They may send a truck or just mail a new modem at some point. I had speed problems on a really old modem and a newer one fixed it right up. Make sure you keep a hard copy of any username and password data somewhere before they touch anything though.

fredf
04-07-2009, 10:59 PM
For the last few months my DSL modem has been loosing
Jason

Jason, has your ISP or the telco checked the line?? I would assume that some steps have been taken? I had a friend who tried to get DSL several times, but couldn't even get a carrier. Her phone worked fine. Finally I convinced her to get them to check everything. apparently there were MULTIPLE bad connections on her line. Has been running happily ever since

Even if you were working OK, some damage could have occurred to the line somewhere between you and the POP.

fred

atty
04-08-2009, 03:42 AM
It may not be your modem at all. We have found out here that the nimwits at the switch had the drop threshold set too high, i.e. when the signal level drops to a certain level, the modem disconnects. Great idea, but if it's not set according to the mean low on your line, you're off more than you're on.

Now all you have to do is 1) find somebody at the telco that understands what you're talking about, and 2) find somebody that knows enough to fix it. That can be quite a challenge.

Dragons_fire
04-08-2009, 09:33 AM
If its a 2wire 2700 gateway, its probably the modem going bad.. it happens all the time with these modems. It could also be a filter, the line or the port but your best bet would be to call your telco and get them to send someone. they shouldnt charge you unless it was something deliberate that you have done to the line thats causing the problems.

Stuart Br
04-08-2009, 09:42 AM
Can you here any audible noise on the line? Last year my ADSL service got very unreliable with continual drops. Analague voice calls on the same line were very noisy. My Telco came in and found a damaged wire that had be trapped during installation, some seven years before. They replaced the cable and the sertvice has been rock solid ever since.

lazlo
04-08-2009, 09:47 AM
You're dropping packets, and it looks like it's because you're losing connection with the other end of the line:

adsl0: down (signal lost)

jacampb2
04-08-2009, 12:15 PM
Thanks for the replies guys. From searching google more, it seems a lot of 2wire (brand) modems are doing this. I have a hard time believing that suddenly the service is crap after more than 7 years of satisfaction.

As to the many suggestions, I have tried most except for calling the phone Co. The phone line running to the jack for the DSL is relatively new. The filter on that line has not been replaced, but I can swap it with one of the other filters in the house.

There is no audible noise on the analog line. I did try removing the filter on this jack all together (just a TS tip I read on line somewhere), but I didn't leave it that way long as the conection statistics showed that the noise had doubled.

I have read that a lot of people are getting this same disconect with ATT and 2wire modems (my same scenario) but most are saying it happens after 9pm, I was thinking maybe it was due to peak bandwidth usage in the area, but I don't really know how all of this plays out with DSL. Mine will drop signal nearly anytime of the day or night, it is especially annoying whenever I am trying to upload something to my web site, anything over a few megs of data, and you are almost gauranteed one signal drop durring the upload time, so I can't upload more than a few megs to my website.

I will call the telco, but I have less than stellar results with their tech support. Most of the time, it is, restart the computer, unplug the modem to reset, check your cables-- nope nothing wrong on our end, it has to be house wiring....

fredf
04-08-2009, 09:19 PM
There is no audible noise on the analog line. I did try removing the filter on this jack all togethe...


I am not real familiar with DSL but I am pretty sure you aren't supposed to use a filter on the modem. as I understand it the filters are to keep the regular phones (modems, answering machines and the like) from sucking up the DSL signal not sure why you would get more noise after removing, but maybe the other end would need to adjust signal levels or something after removal

fred

Dave S.
04-08-2009, 10:02 PM
I work for a telco and installed 3 DSL services today 2 3mg and 1 10mg. Fred is correct that there should be NO filter on the line from the Network interface to the DSL modem. You said the the line to the modem is newer. Call the phone company and if you can get to a real person ask them to come out and install a whole house filter. This will take care of any issues that you may be having with the older wiring in the house.
If you go off hook and kill dial tone by pushing just one key do you hear any noise or static. If you do turn off the modem and recheck if noise goes away if it does you have wireing problems. If noise is still there take a corded phone out to the interface. With a screwdriver open the customer side of the interface. There will be a jack with a short pigtail. Unplug this and plug the phone in. Do the same test again. If there is still noise then the noise is coming from the Telco side and they should fix at no cost. If the noise goes away then the problem is on your side and the Telco will charge you for repairs if you have them test and repair.
Hope this helps

Dave

jacampb2
04-09-2009, 11:50 AM
My filters are HP/LP filters, two jacks, one for the modem and one for the phone. They came with the modem when I bought it, and the instructions said to install a filter on every phone jack in the house, regardless of if it was in use or not.

I have three jacks in the whole house. They are wired with Cat3, 4 wire. Nothing has changed with any of the wiring and it was all new when I moved in, about 7 years ago. I pulled new wire for the modem on the off chance that that was the problem, but no go.

I will kill the dial tone and see if I can hear any noise. That sounds like a good idea. As for the outdoor wiring box and test jack, well that is under the deck on the house. I have access to it, but it will take me a while before I have time to get under there and check.

As far as I can tell from the modems logs, the signal has been very consistent and my noise levels aren't bouncing around. You can see in the log above that it went up and down several times in a few minutes, and all of the signal/noise/power readings remain virtually the same. The other logs show no accumulated errors, in fact the only errors shown in the statistics screen are signal loss events, no packets dropped, no checksum errors, ect...

I am actually hoping it is the modem. I am not looking forward to fighting with the telco over this. I would just as soon go to the Big Box store and buy a new modem.

Later,
Jason

Evan
04-09-2009, 01:08 PM
I had a customer call me to complain that suddenly in the last week or so he kept dropping his dial up connection after only a few seconds after it connected. As we were speaking I heard something that most people would never notice so I asked him to be quiet for a moment. A very slight "tick" sound could be heard every second or so. Because of where he lives I knew what it was so I asked him if he had installed a new fence charger. Sure enough, his neighbor had just electrified a mile of fence that ran next to the phone line. Turning it off fixed it. Not sure what they did about a permanent solution.

There is another more subtle problem that will affect ADSL. In many areas the telco has a shortage of hard wire lines. To solve that problem a unit called a "Pair-Gain" was developed that is a two line multiplexer that can put two digital signals on one wire pair. They are NOT compatible with ADSL. There is a chance that you are now sharing your phone line via a Pair-Gain and you don't know it. The unit is often mounted on the nearest pole that your drop runs to in order to provide another line to somebody else nearby. If some telco idiot installed a Pair-Gain on your line that will explain the problem. They aren't required to tell or ask you about it. Around here they don't even keep track of which lines are on a Pair-Gain.

See here:

http://www.charlesindustries.com/main/te_dualn.html

jacampb2
04-09-2009, 08:59 PM
It looks like I was way off base on my interpretation of the noise figure. I did a brief bit of additional research, and the noise number is actually the noise margin, evidently a different name for signal to noise ratio. Low numbers aren't indicative of the amount of noise on the line, but the of a poor signal to noise ratio. From what I read, for my speed of 6mb/s, the 7db margin figure is borderline for maintaining connection.

This also means I mis-interpreted the data when I removed the filter. The S/N ratio actually improved. The filter is gone again, we will see if it cures it. Otherwise I will move forward with haveing the telco check the line.

Thanks,
Jason