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ccsouth
Premium
join:2012-09-08
Houston, TX

1 edit

Intermittent Disconnects: 3801HGV

Disclaimer: I'm not especially network-savvy--I know a couple things and can connect the dots. However, I am interested in learning, so use small words. Apologies in advance for the longwindedness.

Intro: I've been a U-verse subscriber (18/1.5, internet only) for about 10 months now, and I've been having intermittent connectivity issues from the beginning. Originally, I had another modem, which was the 2wire model typically used by internet-only subscribers (sorry, can't remember model #), but the wireless functionality stopped working after 2 weeks (wired worked fine), so I got it replaced with a 3801HGV (11/2011). My connectivity has been spotty before and after the modem switchout.

The Issue: During a predictable set of time periods (5-9pm weeknights, weekend afternoons), my connection will drop, either via Loss of Signal or Loss of Framing failure. This will continue throughout that time period at random intervals, sometimes in rapid-fire. Sometimes my connection will be rock-solid during one of those time periods, and other times I can't stay connected for more than 10 minutes continuously. Sometimes there will be an entire week (!) in which I don't have any rolling disconnects. However, with the number of times I've reset the modem, I don't really have any comprehensive records from AV Realtime.

Measures Taken:
(1) When I got the modem replacement done, I also asked the Tier 2 agent (and subsequently, the tech) to see if something could be done about the connectivity. From what I recall, the tech replaced a component upstream of the box on the exterior of my house, but downstream of the VRAD (see Disclaimer above) to see if the problem would be remedied. However, the problem has persisted.
(2) I read somewhere (probably here) that dimmer light-switches can interfere with connectivity if the two wires are running in parallel. The location of the AT&T-installed RJ-11 jack is on wall in the living room that also has a dimmer switch for the overhead lights. So, I tried using the jack in the bedroom. It had that new RJ-11 smell to it. Worked like a champ for about a week or two, and then it show the same pattern. The improvement was probably coincidental.
(3) So, I tried using the RJ-11 in the kitchen. {side note: the RJ-11 in the kitchen is where the line comes into the house; the wires going to the other two jacks in the house both run from this main entry line behind the kitchen jack, where they're joined. During installation, the tech cut the wiring to the kitchen's jack, so that the living room's RJ-11 would be connected directly to the main line. In order to relocate the modem, I installed a new CAT3 faceplate in the kitchen.} The frequency of disconnects seems to have decreased slightly, but it could be my imagination.
(4) Tried switching out the line connecting the modem to the wall with a garden-variety telephone cord. Apart from the dubious bonuses of +5 dB attenuation and +1000 ft estimated VRAD distance, it did nothing.
(5) Tried out switching the upstream MTY to 1492 (from 1500); did little or nothing.
(6) Tried specifying "RJ-11" in the line selection, instead of auto; did little or nothing.

Other (possibly useful?) Info:
(1) I rent. My "house" is actually a townhome in a complex of all privately-owned units.
(2) Based only on appearanced, the wiring in my house has probably been there since it was built (circa 1975).
(3) The "Max Rate" listed in UVR seems to have dropped off within the last month or so (was mid-40k Kbps before).
(4) UV Realtime screenshots--
I/P Profile: »imgur.com/jgeI0
Error Table: »imgur.com/WLWIY
Interfaces: »imgur.com/ef2LQ
Bitloading: »imgur.com/WwWaN

Plea: Any ideas about what could be causing this pattern of disconnects? Suggestions and recommendations would be greatly appreciated. I'll be happy to provide more details if needed.

Thanks!

cc

EDIT: formatting


Forosnai

join:2011-09-30
kudos:2
Bit loading shows classic inside wire bridgetap/interference problems (you wouldn't be missing so many bits in the lower tone range). If you had a clean home run from the demarcation to the modem your problems would more than likely vanish.


ILpt4U
Premium
join:2006-11-12
Lisle, IL
kudos:9
Reviews:
·AT&T U-Verse
said by Forosnai:

Bit loading shows classic inside wire bridgetap/interference problems (you wouldn't be missing so many bits in the lower tone range). If you had a clean home run from the demarcation to the modem your problems would more than likely vanish.

In addition, if you are able, try syncing your modem/rg @ the NID test jack, and rerun/repost the realtime screenshots. That would prove whether it is IW bridge tap or outside, or perhaps a bit of both


ccsouth
Premium
join:2012-09-08
Houston, TX

1 edit
said by ILpt4U:

said by Forosnai:

Bit loading shows classic inside wire bridgetap/interference problems (you wouldn't be missing so many bits in the lower tone range). If you had a clean home run from the demarcation to the modem your problems would more than likely vanish.

In addition, if you are able, try syncing your modem/rg @ the NID test jack, and rerun/repost the realtime screenshots. That would prove whether it is IW bridge tap or outside, or perhaps a bit of both

I tried to connecting the RG directly to the NID test jack (red circle below) , but it did not sync over the 20 or 30 minutes I left if connected. Am I doing something wrong?



Forosnai

join:2011-09-30
kudos:2
reply to ccsouth
All the more reason to free up some time to get a few techs to home.


mmay149q
Premium
join:2009-03-05
Dallas, TX
kudos:48
reply to ccsouth
Email uversecare@att.com. with that horrible of a bitloading graph it looks like you're having a bonding an grounding issue as well as a possible bridge tap or metallic fault. Those guys have all the tools to troubleshoot your issue and dispatch a technician accordingly. However I will let you know this most likely won't be fixed by the 1st technician that comes out. I guess it really depends on the tech, but they may be able to significantly improve it. They may need to continue working with you for a while to track everything down depending if you're buried or aerial cable.

Matt
--
Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning. -Albert Einstein


ccsouth
Premium
join:2012-09-08
Houston, TX
Finally got irritated enough to get a tech out to the house.

Before:






After:




The fix? Disconnecting the bedroom jack. Apparently the installer and subsequent tech missed it when looking for issues.

Thanks for all the help--


mmay149q
Premium
join:2009-03-05
Dallas, TX
kudos:48
That would do it, bridgetap in the home it looks like, ouch, sorry you had to go through all that!

Matt