Intermittant cable

[nervex]

Hi all,

Just wondered if anyone is clued up about this stuff, having a problem whereby the upstream/downsteam power keeps spiking.

I've had a total of about 6 or 7 engineer visits now, including managers & a network engineer. They seem to think theres something wrong with the cabinet as i'm the only person in it, and to add insult, all the other newly built houses on this street seem to be getting plugged into another cabinet round the corner.

Heres a brief log of my findings so far, and this is only what i've noticed and it has been happening since I moved in about 2 months ago.


Notes:
- Connectivity state vaires from: Access Denied, Not Synchronized and Upstream parameters aquired
- Upstream modulation changes from ADTMA to DTMA
- Downstream modulation changes from QAM64 to QAM256 and only opens one channel instead of four
- Blue heart icon on V Box HD always seems to flash during these outages too.


Date Time* Duration* Upstream Downstream
Fri 3rd June 9:00 am 1 hour 58.2/61.0 ?
Sun 5th June 1:00 pm 30 mins 58.2 ?
1:45 pm 1 hour+ ? ?
Mon 6th June 1:05 am + 58.2 ?
Wed 8th June 7:54 am 5 mins ? ?
Thurs 9th June 3:05 pm 10 mins 58.2 ?
3:17 pm 3 mins 58.2 ?
Fri 10th June 1:25 pm 6 mins 58.2 42.3
11:00 pm 2 hours+ 58.2 45 * Noticed blue heart icon flasing on V Box HD
Sat 11th June 8:13 am 1 hour 15 mins ? ?
10:00 pm 51 mins 58.2 ?
11:29 pm 1 hour 30 mins 58.2 45


*=Approximate
+=Got bored of waiting and left it

Also I can tell you that they have replaced almost everything equipment wise, swapped modem for a superhub, new internal cables, splitters and isolaters and they even changed a tap-plate in the cabinet (whatever that is).

The guy I'm speaking with is one of the managers whose going to come out and check all my equipment again on monday, though he said he passed the job to 'network' and hasn't heard anything back.

So, any advice?

Cheers

[Peter_]

Your upstream on a Motorola BSR is to high because they do not show levels higher than 58.2 so the is either a local issue with the cabling or cabinet which may need Networks to become involved.

Power levels below for all platforms.

http://www.cableforum.co.uk/board/35251144-post1.html

[nervex]

sorry, could you explain what a motorola bsr is?. i can't really look it up myself at the mo as im havimg to read/ post this from my mobile which is very slow. I have a superhub at the moment amd its been offline since 2:16. Notsure if its a coincidrnce but itz also raining. apologies for typos, touchscreens are hell to tupe on.

ta

[Peter_]

sorry, could you explain what a motorola bsr is?. i can't really look it up myself at the mo as im havimg to read/ post this from my mobile which is very slow. I have a superhub at the moment amd its been offline since 2:16. Notsure if its a coincidrnce but itz also raining. apologies for typos, touchscreens are hell to tupe on.

ta
It is the exchange that you are connected to and may be referred to as a uBR or CMTS, it does not show any higher than 58.2 on the upstream and will require an engineer to rectify the issue.

[nervex]

Ah right ok, well the people who have visited so far haven't found the problem with the cabinet (they refer to it as an "A-cab") although they are sure it's not working properly. I'd like to point out that the downstream power at 45-50 is not a typo (or SNR) and is usually overlooked for whatever reason.

Right now my upstream is 58.2 and my downstream has 4 channels open with QAM64, each around 6-7 dbmv and its working.

I notice that whenever it disconnect the downstream power as in the superhub is reported as over 45 and fluctuates wildly.

After whatever period of time it will return to between 4 and 7 and the upstream usually goes down to 47 too.

[Peter_]

It needs a technician as it will continue to have issues with a upstream that high.

[nervex]

update.. a tech apparantly looked at the cabinet on friday but seems to have undone whatever the network team did to make it better, right now i cant access the net unless the tv box/splitter is disconnected and even then its not as good. its been down for about 9 hours solid right now.

however, the amplifier in the cab is going to be replaced on friday.

[Neo-Tech]

Sounds like a faulty amp to me then!

[Peter_]

Sounds like a faulty amp to me then!
How on earth did you come to that conclusion.:D:D:D

[Neo-Tech]

Well... he mentioned amp, everything else has been replaced and its still not fixed so I think it could be that :D:D

;)

[qasdfdsaq]

Something must be seriously wrong if you are genuinely getting 45-50dB of downstream power. That shouldn't even be possible. Most cable modems get flaky at above ~8-15 and stop working completely between 15-20.

Service quality aside, there's also the issue of dangerous electric levels. At 50dBmV that's 100 volts of AC power coming down your coax line, which would make touching your cable modem equivalent to sticking your finger into a US mains socket. Needless to say this is hazadous to your health irrespective of the RF radiation likely to be coming off it and if it's actually true, then VM could easily be sued to high heaven should you get eletrocuted off their gear.

That said I do severely doubt your average consumer CPE is actually calibrated to be able to measure that much output so it is likely to be misreporting it. But I'd still be careful and avoid going near that coax myself.