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[waltergmw]

Gentlefolk,

Just to add another fascinating ritual to this erudite conversation we have a set of data pertaining to AC20 as BE will testify.
This cct was ordered as a 40 / 2 Profile just to see how bad the initial connection would be.
Perhaps because a full moon was approaching we got some tolerably reasonable speeds for a line well over 1 km in length.
We noted that the upstream was capable of supporting around 5 Mbps so we decided to splash out on a £10 profile upgrade.
SIMPLES !!!! ?
Of coures not !!!
The order was completed with the usual extraordinary efficiency from Zen.
Everything worked perfectly including a new BT speed test saying we now had IP profiles of 22.76 Mbps down & 10 Mbps up.

Here endeth .... BUT NO !!!!
all BT actual speed tests refused to creep even a micron above  2.000Mbps.

Much scratching of everything by us and the indefatigable Zen folk !
It came to pass that we have a banded profile which can only be reset by a SFI BT physical visit to site, even though the problem must be within the configuration data.
We got an appointment the very next day by an excellent local BT Openreach engineer. Unsurprisingly he was clueless as to what a banded profile was and couldn't even open the FTTC anyway due to the fact that there are totally covered and protected 230 Volt components in it ! (The real reason is probably that the managers don't see a need to train such vital but lowly folk in the highly sophisticated equipment therein ! )

Now fortune was on our side as the engineer's JDSU indicated a clear line capacitance fault. This took a morning of thrashing up and down the hill from the EUs house to the PCP cutting and remaking crimps to isolate the faulty component. It turns out the brand new DSLAM tie cables were the cause and the fault was cured. The engineer was convinced that repairing the fault had magically cured our banded profile problem. I suspect his Control had observed that anomaly and then did the reset as a matter of course.

The end result is that we are delighted to have increased the download IP profile by a massive 4.74 Mbps due to the removal of the capacitance problem AND now have full access to the Attainable Net Data Rate:       5093 kbps    up and     27884 kbps  down.

The moral to this story is that we (and no doubt Zen) would have been perfectly happy if the control had been able to reset the banded profile without any engineer SFI appointment. However top marks to the very careful engineer who investigated and cured the entire problem.

Kind regards,
Walter

[burakkucat]

   Hmm . . . I think your posting is worthy of being in a thread of its own, Walter.

[roseway]

I agree. Very interesting and certainly deserves its own thread.

[burakkucat]

Thank you, Eric. 

. . . to AC20 as BE will . . .

To alleviate any confusion over the above abbreviations, I will mention that AC20 is a resident of Ewhurst and BE is baldy bird, Bald_Eagle1, our line analysis expert. 

[Bald_Eagle1]

The moral to this story is that we (and no doubt Zen) would have been perfectly happy if the control had been able to reset the banded profile without any engineer SFI appointment. However top marks to the very careful engineer who investigated and cured the entire problem.

Well done for holding out for the right result Walter & to Zen for pursuing it.

Along with Zen's own data, the statistical data confirming that US sync speed was indeed still capped at exactly 2Mb was obtained via a HG612 on an ECI DSLAM connection.

I wonder though if the same happy result would have been obtained if the user had been stuck with his locked down ECI modem, with the usual "your connection is performing within acceptable limits" and "as your connection's upstream speed has remained below 2Mb, that must be all your connection can achieve" sort of nonsense that I was told about my connection before I unlocked my HG612 modem & saw the stats for myself.

[Black Sheep]

Congrats for perseverance in this matter, Walter.

But, this reads to me as proof-positive that "Just having a profile reset - banding removed", by way of a phone call to the ISP by the EU, is definitely not the way forward. Well done Zen/BT for refusing to perform the reset without an actual engineering visit. That way, the real-life fault (capacitance imbalance) was located and repaired, and only then was the reset carried out, with the knowledge that it is highly unlikely the DLM will re-apply a banding any time in the near future.

Just keep hitting the reset button is not the answer, there is usually a reason behind the DLM's actions. Granted, electrical storms and other extreme high-noise bursts can disrupt the DLM on an otherwise perfect circuit, but these will be in the low percentages.

 

[Ixel]

Congrats for perseverance in this matter, Walter.

But, this reads to me as proof-positive that "Just having a profile reset - banding removed", by way of a phone call to the ISP by the EU, is definitely not the way forward. Well done Zen/BT for refusing to perform the reset without an actual engineering visit. That way, the real-life fault (capacitance imbalance) was located and repaired, and only then was the reset carried out, with the knowledge that it is highly unlikely the DLM will re-apply a banding any time in the near future.

Just keep hitting the reset button is not the answer, there is usually a reason behind the DLM's actions. Granted, electrical storms and other extreme high-noise bursts can disrupt the DLM on an otherwise perfect circuit, but these will be in the low percentages.

 

An interesting thread.

In most cases I'd agree, the reset option should be refused and an engineer visit to check out the issue. When I had a fault I didn't suspect a fault to still exist upon the engineer turning up, credit to the engineer for finding it that morning. According to BT however there's nothing wrong with my line currently, however it's still banded lol. I'll just live with the 20Mbps less, 60/20 is still very fast and gives me the added comfort of a higher SNRM for reliability.

[waltergmw]

@ BS,

I can certainly appreciate your logic when there is a fault.

But if nobody is claiming a fault exists and a customer just wants a regrade, I'm surprised the bean counters within BT would really wish to have the expense of a SFI visit.

We were just lucky we had a fault with the potential to increase the sync speeds.
We were also lucky to be able to prove categorically that the attainable rate had not changed after the original regrade order had been completed to the satisfaction of BT and Zen. Even the speed tests showed the correct faster IP Profile.

Kind regards,
Walter

[Black Sheep]

The problem is, Walter, remote line test systems very rarely pick up a fault that's in its infancy. The DLM will spot it decades before anything else, and will quite rightly apply stabilisation by whatever it deems is appropriate.

So, we have a situation whereby both the EU and the ISP (and Openreach's test systems) all believe the circuit to be OK, whereas in reality something awry is occurring. I am a big believer in having a 'Hands-off' approach with DLM, unless a proven fault has been repaired. Just my thoughts, from years of seeing resets achieve nothing but an eventual engineering visit.

 

[waltergmw]

@ BS,

I much appreciate your ideas and practical approach.

Do you fancy a holiday in the Surrey Hills for a year or five ?  !!!!!!!!!!!!!!

Kind regards,
Walter

[Black Sheep]

Ha ha ...  ... but only if I bring my JDSU with me ..... right    

[Ixel]

Talk of the devil, coincidental but... I had 'BT Fibre' ring me at lunch time, in response to my phone call survey from the second to last call to BT Business, only to try and teach me the basics of DLM and FTTC and that there's nothing they can do to remove my banding as my line is running at the estimated speed, all of which I was told on the previous call anyway.

The operator also tried to tell me that interleaving doesn't exist on FTTC, so I had their time and my time wasted from an unnecessary call to me, congrats to BT call center lol. I'm tempted to write a small email to the CEO's address suggesting that call center staff should be allocated to more important cases than a simple survey response from a phone call I recently had with BT Business.

[Black Sheep]

LOL ..... plus, Interleaving does exist on FTTC, at least that's what my BT remote access tools tell me anyway  .

[burakkucat]

. . . Interleaving does exist on FTTC, at least that's what my BT remote access tools tell me . . .

Just like our line analysis methods! If you have the time available, Bald_Eagle1 will bore enlighten you. 

[Bald_Eagle1]

LOL ..... plus, Interleaving does exist on FTTC, at least that's what my BT remote access tools tell me anyway  .

So does my BT supplied modem, now its secrets have been unlocked.

Has anyone, anywhere, provided a valid and/or official reason as to why the BT supplied FTTC/VDSL2 modems were intentionally locked anyway?

Surely BT must be immensely proud of their fibre/copper technology & would really wish to celebrate the fact that end users can also see (factually) how brilliant their connections really are.