HG612 Modem - Ongoing stats - Power Levels

Hi All,

I am still attempting (after many months) to get to the bottom of why my 800m or so connection is quite unstable & can only sync at around 28Mb to 30Mb.

I have recently had a few days worth of an issue where downstream SNRM levels dropped dramatically when the phone (in the test socket via a dangly filter) was in use.

Even when the phone was not in use, DS SNRM levels dropped dramatically to 2dB or less.

As using the phone caused a further drop in DS SNRM levels, one occasion actually caused the connection to re-sync 4 times within a 10 minute phone conversation.

DS SNRM levels now appear normal & steady again, even when using the phone.

My question is, do any of you who monitor "Ongoing" stats via the Windows graphing scripts see fluctuations in DS power levels.

The available scripts do not currently graph power levels, but I am working on an update that will do so.

In the meantime, this is what my power levels look likethis :-

BE 6 Day Power Levels


In comparison, any other users' connections I have seen look like this:-

Other User 6 Day Power Levels


Arrrgggghhhh!!!!!!

While typing this message, my connection re-synced at only 21172 k - The phone was not in use at the time.

DS SNRM has shot up from 6.1dB to 9.9dB accordingly.

If anyone wants to send me their modem_stats.log for me to graph power levels, please send me a PM including an email address, or post the whole modem_stats.log somewhere that I can download it.


EDIT:

Within a few minutes, DS SNRM had dropped to 2.5dB & just picking up the telephone handset caused it to jump back up to 10dB.

Does this suggest a particular D-side or even a cabinet DSLAM issue to any of our erstwhile engineers?

Edited by Bald_Eagle1 (Wed 28-Mar-12 09:23:13)

total power will be the sum of the individual frequency bands / tones in use, so if the sync speed is changing as some frequency bands become unusable the power will go up and down.

Full sync speed ADSL on short lines always has more output power than slower speeds on long lines.

Fibre uses VDSL

In reply to a post by Anonymous:

Fibre uses VDSL

No it doesn't.

Irrelevant to what yarwell said anyway. He was merely drawing a parallel with the known way the way power and frequency loadings work on ADSL.

In reply to a post by RobertoS:

In reply to a post by Anonymous:

Fibre uses VDSL

No it doesn't.

Yes it does

In reference to www.thinkbroadband.com/guide/fibre-broadband.html:

Fibre to the cabinet (FTTC)

Fibre-to-the-Cabinet (FTTC) involves running fibre optic cables from the telephone exchange or distribution point to the street cabinets which then connect to a standard phone line to provide broadband.

This is combined with a copper cable from the cabinet to the home or business which uses VDSL

The fibre element is NOT VDSL. The copper element from the cabinet to the property is the VDSL2 segment

That's just splitting hairs.

Might be an idea to edit the page the Anon poster linked to Andrew? Completing his selective ( ) quote - "This is combined with a copper cable from the cabinet to the home or business which uses VDSL or similar technology" it might be better to say "VDSL2 or similar technology"?

That's just splitting hairs.

said the poster who wanted to differentiate one flavour of xDSL from another when the principle under discussion is common to both. LOL.

Haven't we got a bit sidetracked here folks? The interesting bit for (not just) me is "what can you reasonably report as an FTTC fault?". When you are talking about superfast, as you do in the news . . . endlessly - and BT for instance on my line quote a speed range as acceptable between 12Mbps and 38Mbps that's a wide range and a materially different level of service, especially problematic when the Quiet Line voice test is OK.

I know the lazy answer is "we don't know" - well it would be nice if someone made an effort to find out, or at least offer some intelligent pointers please! I can surmise that many resyncs (more than one a day?), a fluctuating profile of more than a couple of Meg, or widely varying noise margin of more than a couple of db (if obtainable from the modem) show something is not right, and should your tones also be fairly consistent, but with the OR faceplate your own phone set up is out of the equation? - but that's all a guess. Whilst my own line is not brilliant, but consistent and stable - so I've no complaint - I sympathise with the frustration of those whose lines aren't.

Edited by smurf46 (Wed 28-Mar-12 13:29:17)