Is this normal with FTTC speeds?

Got my FTTC connection in last Monday with Sky and was happy with the 30Mbit down 8Mbit up. A massive improvement on the 1.5Mbit down previously.

However since last Monday the speed has been diminishing. The Sky hub is reporting a speed of 26Mbit down now and any speed tests only shows about 19Mbit.

Is this normal in the opening days of the connection? Or do I have to kick the Openreach device?

Openreach box tends to start as fast as possible, then when experience of errors is built set settings to make line stable, i.e. slower but with less error packets.

The Openreach modem if there was a noise burst, e.g. lightning will stay at the slower speed till someone kicks it, so a reboot if slow and you have not rebooted it for a few days is reasonable

Restarted the Openreach box and speed dropped even more. Was advertised as 27.9 down currently getting around 24 down. On days 1-3 was connected at 30 down and it was flying.

Not anymore.

Latest test is 16Mbit

In reply to a post by da_flash:

Latest test is 16Mbit

On the plus side you'll soon be in fault territory so Sky can get an engineer out.

In reply to a post by da_flash:

Is this normal in the opening days of the connection? Or do I have to kick the Openreach device?

If you are getting errors in the VDSL2 data transfer, then DLM will intervene, and attempt to get rid of those errors - usually by adding a level of FEC and interleaving.

If the intervention isn't enough, then DLM will intervene further, setting higher levels of FEC and interleaving, until it finds a setting where the errors disappear, or at least minimise.

In the most extreme cases, it may also add "banding" where it restricts your sync speeds.

Most interventions cause a reduction in sync speed and an increase in latency.

Usually, your line is left to run free for the first two days, and DLM will only intervene on the third day. If it does, you will see a resync somewhere between 2AM and 8AM overnight. Further interventions are likely to be at similar times on subsequent days.

Kicking the Openreach modem almost never has an effect.

If the cause of errors gets removed, then it can take a number of weeks for DLM to reduce or remove the intervention. Kicking the modem won't speed this process up either.

Well a couple of my speed tests hit the 14Mbit mark. The lady in the fibre team at Sky didnt want to know. She told me to do a hard reset on the Openreach modem and said any more problems call back.

Pretty poor really.

These speed tests via wireless or wired?

Wired

Perhaps you need to unlock the modem if it's an HG612, if it's not you can pick one up off ebay pretty cheaply.

You'll then be able to collect some stats and post them on here.

Am surprised the lady from Sky told you to reset the Openreach modem.

As far as I was aware you definately shouldn't be resetting that yourself at least for a while as the DLM will believe the line has lost sync and lower the rate. If someone could confirm/deny please.

My connection is on the lower end, started at 27mb (about 2.9mb p/s download) and went down in stages all the way to syncing at 18000 which gave me about 2mb p/s download and now back up to sync at 22.5 and download of 2.5mb p/s. Bearing in mind that I had my fibre installed in December, had 6 engineer visits due to line problems but the last was in February. So in the 5 months since then it only went up to 22.5 from 18 about a week ago.

On longer lines (Which I assume yours is) the engineers told me that DLM is essentially broken, I was advised if it kept dropping (as it had gone as low as 7mb when first installed) just to ring up and request a DLM reset. As soon as that was done on the engineer visits it happily connected at 26-27MB but the DLM just drops way too much on a disconnect.

Edited by deleted (Fri 12-Jul-13 17:47:43)

Why would a single resync cause dlm to drop speed? If there is a thunderstorm we can expect the whole region to plummet and stay slow for weeks on that basis

It's perfectly normal to see significant decrease in the first few weeks as it finds a totally stable speed.

The initial speed would have had error build up and likely drop outs. You wouldn't notice the drop outs probably as they last a few seconds at a time.

The best way to ensure the best speeds is to leave the equipment connected 24/7. It is evident that you're not doing this as you can see the speed changing in the Sky Hub.

The speed only changes on a reboot.

E.g. say the line sycs at 40Mbps. 1 day later DLM may change the line to 30Mbps.
The Sky hub would still show 40Mbps 1 day later, even 20 days later. For it to update the speed it needs a reboot.

So you are clearly rebooting. If the modems being rebooted often you will see extremely significant losses.

You don't have to reboot it, just start a new session by disconnecting the ethernet cable from the router until the @ light goes out then plug it back in. The connection speeds will then update with the actual sync speed in the routers "stats" page.

Fair play but I doubt the op has been doing that. Much more likely a reboot.

In reply to a post by ukhardy07:

Fair play but I doubt the op has been doing that. Much more likely a reboot.

Could be rebooting router, and leaving modem - that shouldn't affect DLM.

True but again it's more likely to be both as it's likely they didn't realise the negative affect it could have.

No reboots fellas. Only the one reboot Sky advised me to do by holding the reset button for 10 seconds on the Openreach router.

ironically my attainable jumped at the weekend and hasnt gone down since yet.

I havent rebooted the modem as I currently have a good sync uptime and I am not confident it wont go down again so just leaving it with a higher snrm at the moment.

Relogged this with sky as speed tests were hitting only 12Mbit

Expecting a call back

=~=~=~=~=~=~=~=~=~=~=~= Plink log 2013.07.17 17:41:07 =~=~=~=~=~=~=~=~=~=~=~=

xdslcmd info --stats

xdslcmd: ADSL driver and PHY status

Status: Showtime

Retrain Reason: 2

Max: Upstream rate = 7718 Kbps, Downstream rate = 27568 Kbps

Path: 0, Upstream rate = 8087 Kbps, Downstream rate = 20782 Kbps



Link Power State: L0

Mode: VDSL2 Annex B

VDSL2 Profile: Profile 17a

TPS-TC: PTM Mode

Trellis: U:ON /D:ON

Line Status: No Defect

Training Status: Showtime

Down Up

SNR (dB): 8.9 5.0

Attn(dB): 0.0 0.0

Pwr(dBm): 11.2 6.4

VDSL2 framing

Path 0

B: 63 238

M: 1 1

T: 54 22

R: 16 16

S: 0.0979 0.9397

L: 6535 2171

D: 329 1

I: 80 255

N: 80 255

Counters

Path 0

OHF: 75714708 1049694

OHFErr: 398 274

RS: 3675847794 3228588

RSCorr: 244825351 4900

RSUnCorr: 15465 0



Path 0

HEC: 3480 0

OCD: 0 0

LCD: 0 0

Total Cells: 3440889649 0

Data Cells: 3551494686 0

Drop Cells: 0

Bit Errors: 0 0



ES: 640 242

SES: 534 6

UAS: 70 70

AS: 301488



Path 0

INP: 3.00 0.00

PER: 3.96 15.50

delay: 8.00 0.00

OR: 48.40 20.12



Bitswap: 138135 143



Total time = 1 days 19 hours 52 min 32 sec

FEC: 352285304 6412

CRC: 116005 419

ES: 640 242

SES: 534 6

UAS: 70 70

LOS: 340 0

LOF: 15 0

Latest 15 minutes time = 7 min 32 sec

FEC: 25 1

CRC: 0 1

ES: 0 1

SES: 0 0

UAS: 0 0

LOS: 0 0

LOF: 0 0

Previous 15 minutes time = 15 min 0 sec

FEC: 594 0

CRC: 3 0

ES: 1 0

SES: 0 0

UAS: 0 0

LOS: 0 0

LOF: 0 0

Latest 1 day time = 19 hours 52 min 32 sec

FEC: 93792 4614

CRC: 8 165

ES: 3 57

SES: 0 5

UAS: 0 0

LOS: 0 0

LOF: 0 0

Previous 1 day time = 24 hours 0 sec

FEC: 1650239 37

CRC: 11 7

ES: 4 8

SES: 0 0

UAS: 0 0

LOS: 0 0

LOF: 0 0

Since Link time = 3 days 11 hours 44 min 47 sec

FEC: 244825351 4900

CRC: 398 274

ES: 25 148

SES: 3 5

UAS: 0 0

LOS: 0 0

LOF: 0 0

xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 2
Max: Upstream rate = 7718 Kbps, Downstream rate = 27568 Kbps
Path: 0, Upstream rate = 8087 Kbps, Downstream rate = 20782 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959) (2792,4083)
Medley Phase (Final) Band Plan
US: (0,95) (880,1195)
DS: (32,859) (1216,1959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 7718 kbps 27568 kbps
Actual Aggregate Tx Power: 6.4 dBm 11.2 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 5.1 50.0 66.8 N/A 21.6 61.8 0.1
Signal Attenuation(dB): 5.1 49.8 N/A N/A 21.6 61.8 N/A
SNR Margin(dB): 5.4 5.0 N/A N/A 8.9 8.4 N/A
TX Power(dBm): -3.6 6.0 N/A N/A 10.7 1.1 N/A

xdslcmd info --Bits
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 2
Max: Upstream rate = 7718 Kbps, Downstream rate = 27568 Kbps
Path: 0, Upstream rate = 8087 Kbps, Downstream rate = 20782 Kbps

EDIT: I misread the stats. I read it like I would read an ADSL2+ stats without even considering I was reading fibre stats so I took the 1st two SNRs and stopped reading... My mistake!

I'd get Sky to send somebody out if possible.

Edited by ukhardy07 (Thu 18-Jul-13 16:57:56)

I think this tells the story

Discovery Phase (Initial) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959) (2792,4083)
Medley Phase (Final) Band Plan
US: (0,95) (880,1195)
DS: (32,859) (1216,1959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 7718 kbps 27568 kbps
Actual Aggregate Tx Power: 6.4 dBm 11.2 dBm
============================================================================
VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 5.1 50.0 66.8 N/A 21.6 61.8 0.1
Signal Attenuation(dB): 5.1 49.8 N/A N/A 21.6 61.8 N/A
SNR Margin(dB): 5.4 5.0 N/A N/A 8.9 8.4 N/A

The SNR is 8.9
Only 2 bands have been selected as the attenuation is so high.
There may be a line fault, or aluminium wiring.

What was the estimated speed at sign up? Just out of interest. You may have already put this somewhere as I've honestly been dipping in and out of this. If so sorry to make you repeat. It just helps to judge whether there's a line fault a little better.

Edited by ukhardy07 (Thu 18-Jul-13 17:00:20)

Had a fibre SFI.

Openreach rocked up I told him Kelly Comms did my install and immediately he changed the faceplate and the Openreach modem.

I know have the ECI model.

Anyways no errors on the line this tested fine. He did a DLM reset and got my 30Mbit back. Engineer even tidy'd up their cabling which comes through the stairs.

His conclusion dodgy Openreach modem.

Been rock solid since. Touch wood!!!!!!