daveinpoway
join:2006-07-03
Poway, CA
| reply to Morac
Re: [Connectivity] My neighbor and I are having major connection
The second set of numbers (4/29/08, 1:44 PM) looks strange. A 0 dB downstream signal/noise ratio means that the signal and the noise are equal; either your connection has some serious problems or else the modem is defective and is reporting the wrong value. |
|
Morac
join:2001-08-30
Riverside, NJ
 ·Comcast
edit:
May 7th, @08:17AM
| said by daveinpoway  :The second set of numbers (4/29/08, 1:44 PM) looks strange. A 0 dB downstream signal/noise ratio means that the signal and the noise are equal; either your connection has some serious problems or else the modem is defective and is reporting the wrong value. I thought that was strange myself, but since the Comcast person on the phone gave me that number (I wasn't home at the time) I figured he got it wrong. Every time I check the signals on my modem when I'm having loss they are fine.
The upstream SNR's are way off though. What makes no sense is last night I was having major problems (16% loss) and the person on the phone said I had a 12.8 dB upstream SNR. He said his screen showed that 12.8 dB was "green", meaning good. From the FAQ on this site it says it should be over 29 dB.
I'm convinced it's an upstream problem, but it's intermittent (some days are good, some are bad) so I don't know what's causing it.
I changed my appointment to this morning from 10 AM to noon since the problem is occurring now (though the packet loss is currently low). I'm just hoping I don't have to take off from work for no reason.
Here's my current line quality test. As you can see basic pings are now good, but high bandwidth pings are failing.
»/linequality/nil/2381737 |
|
K Patterson
Premium,MVM
join:2006-03-12
Columbus, OH
·RoadRunner Cable
| Here's some information, but no solution.
The SNR's reported by your modem and by thhe CMTS are not based upon actual measurements. They are estimates based upon the observed error rate. That rate is plugged into formulas developed by a guy named Shannon years ago. Since the signal level of all modems on an upstream is the same or nearly so, it is an estimate of how much noise is arriving at the CMTS, and would be the same for all folks on the upstream if the only issue was noise. Unfortunately this measurement cannot distinguish the other potential problems including amplifier and node distortion and modulation errors in your modem, which can vary from user to user.
So, if they are on the ball, when they see that you have a bad upstream SNR, they will look at other modems on the upstream and see if it is a common problem, or perhaps common to a group of modems in the same area of the cable plant.
At this point I would replace the modem if you have not done so already. Other than that, all you can do is keep after them. |
|
Morac
join:2001-08-30
Riverside, NJ
·Comcast
edit:
May 7th, @09:54AM
| said by K Patterson :At this point I would replace the modem if you have not done so already. Other than that, all you can do is keep after them. I had major problems back in October and they replaced my modem 3 times back then until they finally tracked down an intermittent upstream issue.
Somehow I doubt my modem is the problem in this case since if the modem was bad I would think the problem would be occurring all the time, not every other day or so. It also wouldn't explain why my neighbor is having problems.
I'm convinced if I could get a line tech out when the problem was occurring I could get this fixed. The problem is a) getting a line tech out and b) getting one out when the problem is occurring.
As for squirrels, all the lines in my development are underground so I don't think it's "line chewing". Plus my digital TV pictures are fine (99% of the time).
It's about 7 minutes until the 2 hour window when the tech is supposed to come and the problem is still occurring so hopefully this time I'll get results. |
|
K Patterson
Premium,MVM
join:2006-03-12
Columbus, OH | My point about the modem is that by exchanging it you would rule it out and leave one less hole for the mice to hide in. I agree that it is probably not the cause. |
|
plat2on1
join:2002-08-21
Hopewell Junction, NY
clubs:
edit:
May 7th, @01:53PM
| reply to Morac
you are right about needing a line tech from what i'v been told regular techs don't have the equipment or training to diagnose and fix these types of issues
if you hit a roadblock with the normal methods go this route
»Comcast High Speed Internet »How do I contact the Comcast Executive Complaint Center? |
|
Morac
join:2001-08-30
Riverside, NJ
·Comcast
| Thanks for the link. I got a lead tech out (coincidentally the same one I had from last October) and he saw the problem. At the local office they saw that modems in a small radius around my block were having all kinds of signal issues so a line tech was scheduled for sometime today.
Of course, according to the Smokeping, everything cleared up right after the tech left. Hopefully the line techs don't (didn't) just assume everything is now working and leave it at that since from experience the problem will return in a day or two.
At least the wheel is getting some grease now. |
|
