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[Dave2150]

My input was really for Dave (and other folk who may be unawares), that a lot of time could be spent for no return on a loss of 6Meg after transferring ISP's. I understand Dave's frustration, just didn't want his hopes built up. 

Oh, my complaint about Aluminium wasn't about the 5-6Mbit of sync I lost, following my migration from Sky to BT. This is simply down to DLM capping my line at 27Mbit, I'm simply waiting for it to return to it's usual value on my line.

My complaint about Aluminium stems from the fact that my next door neighbour, who's house shares the same ducting as mine, gets a much higher sync. Both houses have copper lines underground to the second BT pole (as this infrastructure was built 10 years ago with the houses) but from there his line is either copper all the way to the cabinet, or following a much shorter route to the cabinet. One of the two.

At the moment my main aim is to determine why DLM hasn't relaxed my line to a 6DB noise margin for the downstream.

[Black Sheep]

How many blocks are at the top of the pole that feeds yours and your neighbours premises ?? If there are two different blocks, there's a chance that one could be copper cable and the other ali ?? This would only usually be what we call the 'Tail' ..... ie: from the pole-top block to the underground box. From here it would usually pick up the same 'feed' cable provoding service to the other pole-top block.

Of course, the scenario could play out where there is no spare capacity in the original 'feed' cable to supply further 'pairs', and therefore a totally new cable would have to be provided.

However, there is no way of knowing without either physically looking at the cable node, or by viewing the duct/cable prints.

[Dave2150]

How many blocks are at the top of the pole that feeds yours and your neighbours premises ?? If there are two different blocks, there's a chance that one could be copper cable and the other ali ?? This would only usually be what we call the 'Tail' ..... ie: from the pole-top block to the underground box. From here it would usually pick up the same 'feed' cable provoding service to the other pole-top block.

Of course, the scenario could play out where there is no spare capacity in the original 'feed' cable to supply further 'pairs', and therefore a totally new cable would have to be provided.

However, there is no way of knowing without either physically looking at the cable node, or by viewing the duct/cable prints.

The (7) houses all had underground ducting installed at the time the houses were constructed (10 years ago, so all copper) . A new BT pole was erected at the top of the street. The underground ducts that connect all 7 houses emerge at this bt pole. From there, there is a single cable bundle (looks an inch thick) that travels 20M or so to an extremely old Ivy covered shared electricity/telephone cable pole. From here there are a massive number of BT cables going in all directions, so I have no idea which direction my cable is going in.

[Dave2150]

Still capped at 27398Kbps - despite the attainable being 38448Kbps.........

I've read that this speed 'banding' seems to be a permanent feature for some users. Does anyone have any experience of getting it reset? My SNR doesn't vary too much, syncs at 8.8DB during the day and drops to 8.0/8.1 in the evenings.

Considering the fact that my line was stable at 6DB and was able to sync at 33, 34mbit with Sky - I feel it's reasonable to request a DLM reset, or just for the speed banding to be removed.

[Bald_Eagle1]

FWIW, I'm currently remotely monitoring another connection where speeds are capped.

This connection has exhibited very few errors during the period I've been monitoring it & it has quite high SNRM levels, which would normally allow higher sync speeds.

It was capped at these speeds until the connection resynced & had G.INP applied (Huawei DSLAM):-

Max:   Upstream rate = 7613 Kbps, Downstream rate = 39624 Kbps
Bearer:   0, Upstream rate = 6000 Kbps, Downstream rate = 27398 Kbps


Following the resync, these were the speeds:-

Max:   Upstream rate = 7337 Kbps, Downstream rate = 42876 Kbps
Bearer:   0, Upstream rate = 6000 Kbps, Downstream rate = 27400 Kbps


Here's the pbParams data:-

Code: [Select]


xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 1
Last initialization procedure status: 0
Max: Upstream rate = 7337 Kbps, Downstream rate = 42876 Kbps
Bearer: 0, Upstream rate = 6000 Kbps, Downstream rate = 27400 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Discovery Phase (Initial) Band Plan
US: (7,32) (871,1205) (1972,2782)
DS: (33,859) (1216,1961) (2793,3959)
Medley Phase (Final) Band Plan
US: (7,32) (871,1205)
DS: (33,859) (1216,1961)
  VDSL Port Details   Upstream   Downstream
Attainable Net Data Rate:      7337 kbps     42876 kbps
Actual Aggregate Tx Power:        2.3 dBm      11.2 dBm
 =========================================================================================
  VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
  Line Attenuation(dB): 8.0 44.7   N/A   N/A   N/A 20.2 56.4 86.3
Signal Attenuation(dB): 8.0 44.1   N/A   N/A   N/A 22.4 56.0   N/A
SNR Margin(dB): 15.3 15.3   N/A   N/A   N/A 14.6 14.6   N/A
TX Power(dBm): -8.9 1.8   N/A   N/A   N/A 8.8 7.6   N/A


The speeds had improved in steps following rearrangement of some user-side cabling that was causing issues, but as we don't have a valid reason to request a DLM reset, we'll just have to wait & see if DLM eventually relents.
I suspect you'll have to also do the same.

[WWWombat]

Its a good point in there ... A user fixing a wiring issue in user-owned wiring is just as valid a reason for a DLM reset as an Openreach engineer fixing openreach-owned wiring.

Does this become inadvertent discrimination to a homeowner from installing and maintaining his own wiring? An anticompetitive measure?

[Chrysalis]

I think you just gave william an idea :p

[Dave2150]

Update, contacted BT via live chat support, engineer booked for Tuesday the 19th!

Presumably the engineer will simply make the call to reset my DLM after he has "checked the cabinet".

Here's a screenshot of the livechat for anyone interested (edited out personal info as well as the agent's Surname)

[Dray]

Presumably as he has called an engineer, the tools have detected a line fault which the engineer will be tasked to fix. When he's fixed the fault, he may then request a DLM reset.

[Dave2150]

Presumably as he has called an engineer, the tools have detected a line fault which the engineer will be tasked to fix. When he's fixed the fault, he may then request a DLM reset.

I doubt the tools detected any line faults, since my voice line is working perfectly as is my VDSL (same line). Perhaps the tools detected a cabinet problem, though it seems unlikely to me.

I really think he just understands that this is the only way to remove the DLM banding - though I'd like to see the reason he entered for the engineer visit, as from what I understand they are not allowed to call out an engineer for just a DLM reset.

[William Grimsley]

It'll certainly be interesting to see what happens, thank god I'm getting unbanded on Monday, I might have had to use this "trick" otherwise!

[Dave2150]

The BT engineer came today as planned.

First he tried his handheld modem/test equipment in my SSFP, but this failed to sync. I suggested it might be because it's an ECI cabinet and has G.INP active, he wasn't sure. I showed him the current/max attainable sync and SNR etc on my laptop, he seemed amazed I could access such data.

After 20 minutes of trying to sync with his equipment, he phoned HQ to try get a reset done. He was on loudspeaker so I was able to listen in. The person on the other end immediately confirmed I was banded but was extremely reluctant to want to remove said banding. He mentioned to the engineer that his equipment should have an option for him to do a reset himself - the engineer was unaware of this and didn't seem to accept it was possible. A heated debate commenced, was quite interesting to hear internal communication between engineers.

At the end of the phonecall, he said to me that he was going to visit the cabinet to do the reset, since the person he called didn't want to help. He said he'd return soon. 5 minutes later I notice my modem loose sync, then resync unbanded Back to my usual 33mbit that I had with Sky, 6DB SNR. Once G.INP reactivates  I hope the sync will manage 35-36mbit.

New line stats:



Fingers crossed that G.INP activates on my line before DLM decides to band it again! Current ES are quite high - when I was on G.INP these were completely eliminated for me, and max attainable went up to 38mbit.

[Dave2150]

IP profile hasn't updated yet, assuming this will take a few hours to kick in? 

[NewtronStar]

IP profile hasn't updated yet, assuming this will take a few hours to kick in?

If the modem and router are separate from each other you could turn off/on the router for a few minutes to initiate a new PPPOE session that should change the IP profile.

[Dave2150]

IP profile hasn't updated yet, assuming this will take a few hours to kick in?

If the modem and router are separate from each other you could turn off/on the router for a few minutes to initiate a new PPPOE session that should change the IP profile.

That did the trick, thanks for the information

Glad I didn't have to power cycle the modem, leaving that well alone in the hope that G.INP gets activated before I get banded again! I doubt DLM likes the amount of errors on my line without it.