Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: elliottchandler on April 08, 2018, 09:50:09 PM
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Hi, recently changed from Gamma Telecom to Plusnet for Business and have now lost 6MB in download and around 1 in upload. The router has stayed the same just changed the ISP. Please see current xdsl stats from the Zyxel VMG8324-B10A. The ISP has said that the line is fine but it doesn't make sense.
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VDSL Training Status: Showtime
Mode: VDSL2 Annex B
VDSL Profile: Profile 17a
G.Vector: Disable
Traffic Type: PTM Mode
Link Uptime: 17 days: 10 hours: 13 minutes
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VDSL Port Details Upstream Downstream
Line Rate: 2.030 Mbps 15.057 Mbps
Actual Net Data Rate: 2.011 Mbps 14.999 Mbps
Trellis Coding: ON ON
SNR Margin: 6.0 dB 3.4 dB
Actual Delay: 0 ms 8 ms
Transmit Power: 6.3 dBm 6.4 dBm
Receive Power: -11.6 dBm -22.5 dBm
Actual INP: 0.0 symbols 3.0 symbols
Total Attenuation: 0.0 dB 26.7 dB
Attainable Net Data Rate: 1.968 Mbps 16.441 Mbps
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VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
Line Attenuation(dB): 7.1 57.1 61.1 N/A N/A 23.9 69.9 N/A
Signal Attenuation(dB): 7.1 56.8 N/A N/A N/A 33.0 69.5 N/A
SNR Margin(dB): 5.6 6.0 N/A N/A N/A 3.4 3.6 N/A
TX Power(dBm): -4.6 5.9 N/A N/A N/A 10.4 3.6 N/A
====================================================================================
VDSL Counters
Downstream Upstream
Since Link time = 13 min 35 sec
FEC: 11823397 1446
CRC: 5072 150
ES: 631 129
SES: 30 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 13 min 59 sec
FEC: 967 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 1044 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 10 hours 13 min 59 sec
FEC: 266238 16
CRC: 152 1
ES: 39 1
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 24 hours 0 sec
FEC: 202272 33
CRC: 48 4
ES: 30 4
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Total time = 1 days 10 hours 13 min 59 sec
FEC: 11823397 1446
CRC: 5072 150
ES: 631 129
SES: 30 0
UAS: 23 23
LOS: 0 0
LOF: 0 0
LOM: 0 0
====================================================================================
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Just adding the results of the line checker.
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recently changed from Gamma Telecom to Plusnet for Business and have now lost 6MB in
At a guess it would indicate that G.INP was removed if this line is on a Huawei Cabinet, the amount of people who still don't understand this is unbelievably.
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At a guess it would indicate that G.INP was removed if this line is on a Huawei Cabinet, . . .
I would agree with that assessment.
It's just a case of wait for G.998.4 (G.Inp) to be reapplied to the circuit . . . assuming that the cabinet is equipped with a Huawei DSLAM.
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Can you telnet in and run adsl info --Vendor
I recall from a previous thread that you had a port swap done by OpenReach which swapped your line from an ECI DSLAM to a Huawei DSLAM.
I'm interested to see if you're still on a Huawei cabinet.
As NStar pointed out the reason is likely the absence of G.INP.
Your line likely had G.INP with a 3dB SNRM target
It is now interleaved. This happens with an ISP switch.
How long since the switch?
Do you monitor the line with DslStats?
edit: the line is running at 3.4dB downstream, though I would expect it to be on a 6dB target. This may be a new crosstalker taking 3dB. It would explain why your attainable isn't significantly higher than actual, as is usually the case with interleaving.
TL:DR
It should gain some speed from DLM in the next few days/weeks. This is expected behavior
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When you mention G.INP are you referring to G. Vector? I cannot see how you obtained that G.INP is not available. ISP switch is now 18 days. I will try telnet command tomorrow. I am not running dslstats at the moment.
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When you mention G.INP are you referring to G. Vector? I cannot see how you obtained that G.INP is not available. ISP switch is now 18 days. I will try telnet command tomorrow. I am not running dslstats at the moment.
No, G.Vector is different, that's known as Vectoring.
We can tell G.INP is off from the INP figure being 3.
Actual INP: 0.0 symbols 3.0 symbols
Tells us the line has traditional interleaving.
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When you mention G.INP are you referring to G. Vector?
No see ~ Is G.INP similar to Vectoring? (http://www.kitz.co.uk/adsl/retransmission.htm#retransmission-v-vectoring)
I cannot see how you obtained that G.INP is not available.
G.INP isn't currently applied to your line. This bit from your stats tell us that your line has old style INP (interleaving) applied
Actual INP: 0.0 symbols 3.0 symbols
INP 3 and Target SNRM of 6.3dB is the default profile after a DLM reset, which can occur after a change of ISP. Hopefully after a few weeks, G.INP will be re-applied and as such will increase your line rate.
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ETA
My post crossed with J0hns and I had already typed this, so leaving as is despite some repetition.
Warning - while you were typing a new reply has been posted. You may wish to review your post.
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Thanks for the information. So I should wait another week or so to see if sync speeds improve? Is there anything else that could be affecting download and upload speed?
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So I should wait another week or so to see if sync speeds improve?
Yes.
Is there anything else that could be affecting download and upload speed?
There is nothing obvious.
When time permits, please run the command that j0hn mentioned and show its output . . .
xdslctl info --vendor
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Output from Telnet
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 1948 Kbps, Downstream rate = 17534 Kbps
Bearer: 0, Upstream rate = 2011 Kbps, Downstream rate = 14999 Kbps
ChipSet Vendor Id: IFTN:0xb206
ChipSet VersionNumber: 0xb206
ChipSet SerialNumber: 5502174580
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Ouch.
Is this the same line you were using as cwave on MyDSLWebStats?
Do you have multiple lines or was there a break in your service?
You had both DSLAM Vendors last time you posted.
That was on a Huawei cabinet with G.INP
Your now connected to an ECI cabinet. G.INP isn't working with ECI cabinets.
So no expected improvement I'm afraid.
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You are connected to an ECI cabinet so you will not have the benefit of G.Inp at present, BT and ECI have been trying to fix this for a year or 2 but have not sorted it out yet.
It looks like your line has been banded (i.e. capped) at 15Mbps but your SNRM is rather low at 3.4dB which is odd. Have you tried a single resync to see if the speed changes?
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j0hn - yes this is the same line. Stange that it might have had a different vendor last time?
RealAleMadrid - I have seen info on ECI cabinets. How do you do a 'single resync'? How does the line get banded? This line used to achieve 21 Mbps 2 years ago.
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Lines usually get banded/capped from too many resyncs in a short period of time. I wouldn't recommend doing a resync. If it is banded it cannot go any higher.
You may even sync lower, especially with such a low SNRM.
At your local green PCP cabinet you have 2 different Fibre cabinets, both an ECI & a Huawei.
You were originally connected to the older ECI cabinet.
Then you had an OpenReach engineer visit around Feb 2017 and they did a "lift & shift" and swapped you to the better Huawei cabinet.
We discussed your cabinet changing in this thread (http://forum.kitz.co.uk/index.php/topic,18678.msg342096.html#msg342096).
You have either had a subsequent OpenReach engineer visit and they swapped you back, or you had a break in service at some point.
There's no need to change port during an ISP switch unless something went wrong.
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I don't think it is banded as with the DS SNR Margin at 3.4dB there isn't any more speed to be had.
The error stats look very good too.
If the line is now on an ECI cab then G.INP won't be making an appearance any time soon unfortunately :(
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Actually since Feb 2017 the service was switched from BT Wholesale to Gamma and then just over two weeks ago to PlusNet Business. Each time losing download and upload. What can be done to recover this loss of download and upload?
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You would need to convince Plusnet to send an engineer to do a port swap, switching you from the ECI cabinet to the Huawei. OpenReach refer to this as a "lift & shift".
I don't know if it's even possible for them to do this. The system might just pick any free working port.
Convincing Plusnet to do this would be very difficult. Finding someone who understands your request might be a stretch.
Then they would need to convince OpenReach to change your perfectly working port.
It would likely set a precedent. Having both cabinet Vendors on the same PCP is becoming more common.
I'm not sure OpenReach would allow this.
I did what you want to do, but I ceased my line and reactivated it to achieve this.
I didn't even try requesting it as I wouldn't expect them to do it.
You could also try ordering a 2nd line in the hope that gets commissioned on the Huawei cabinet.
I don't think it is banded as with the DS SNR Margin at 3.4dB there isn't any more speed to be had.
The line is interleaved but the attainable isn't as high as I would expect.
Looks to me like the line has synced at 6dB, and dropped to 3.4dB some time after sync. This had lowered the attainable too.
I'd still guess the line is banded. It may even sync lower than that figure next resync though.
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I'm not sure OpenReach would allow this.
I'm sure that in another post BS said it wasn't... for the reasons you have already mentioned.
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j0hn, thanks for the reply. So after you ceased and reactivated you got a different DSLAM? Huawei?
I am struggling to understand why a service that once achieved 21Mbps is dropped so significantly. I know that it is working but it is incredulous that the download speed is being eroded away and Openreach consider it acceptable.
I will have a go at a lift and shift as have been successful at this previously.
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Is there any reasonable explanation as to why the erosion on the download and upload?
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Cross talk, line faults, Rein/Shine.
My upload has dropped from 12 to as low as 6 and is currently at 8Mbps. Download has varied between 55 and 38 over the 6 years I've had it.
By the way if you cease and reactivate you'll still be on the ECI cab, you need either a new line or down grade to ADSL, even then there are no guarantees of getting on the Huawei cab.
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Ronski, thanks for the reply. I was beginning to think that we are looking at some kind of fault. I just struggle to understand why when merely changing ISPs that the download would drop by 4Mbps. I can't seem to find any reason for that. I know DLM will probably been involved but losing 4Mbps because of a change in provider seems odd.
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It's a long shot...but low interleaving has been applied to the line. Was it previously interleaved or fastpath? There was an announcement late last year that Openreach were trialing putting new ECI lines on low interleaving rather than fastpath:
https://www.ispreview.co.uk/index.php/2017/11/openreach-test-low-level-error-correction-fttc-broadband-lines.html
(https://www.ispreview.co.uk/index.php/2017/11/openreach-test-low-level-error-correction-fttc-broadband-lines.html)
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Hi Gary, I don't have any data to know whether it was on fast path or not?