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Standard User giggsy1977
(member) Mon 12-Nov-18 07:28:30
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Noise margin increased (Sky FTTC)


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Hello all. I am on the Sky 40/10 FTTC package and currently get 37 down and 9.5 up. I am also to be upgraded to Sky's faster package for free over the next few months according to the email they sent. I noticed yesterday that my noise margins for both up and down have increased (download noise margin from 9.5db to 13db, and upload from 9.9db to 10.10db). Is this likely to be noise on the line, or conversely I am likely to see a healthier increase in speed when switched over to the faster package do you think, given the possible improvement in headroom? Many thanks.

BT Infinity 2 - Predicted speed 54.7Mbps down/15.7Mbps up. Actual speed 42Mbps down/4.5Mbps up...crazy Left BT as they were poor...
Now with Sky Fibre - 37.5Mbps down, 9.5Mbps up
Router stats - Connection speed 40000 kbps down, 9997 kbps up - Line Attenuation 19.3 dB down, 0.0 dB up - Noise Margin 9.8 dB down, 9.9 dB up.
Standard User AndyPandy
(fountain of knowledge) Mon 12-Nov-18 10:24:02
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Re: Noise margin increased (Sky FTTC)


[re: giggsy1977] [link to this post]
 
This would indicate less noise on the line, so faster speeds once upgraded. It is the "safety margin" between the signal, and noise.


ZeN Unlimited Fibre 2
Fritz!Box 3390
Standard User giggsy1977
(member) Mon 12-Nov-18 13:14:35
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Re: Noise margin increased (Sky FTTC)


[re: AndyPandy] [link to this post]
 
Thanks AndyPandy. Good to know. I thought it might have gone up because there was more noise on the line, then once I upgraded the speed might be lower until the noise lowered again!

BT Infinity 2 - Predicted speed 54.7Mbps down/15.7Mbps up. Actual speed 42Mbps down/4.5Mbps up...crazy Left BT as they were poor...
Now with Sky Fibre - 37.5Mbps down, 9.5Mbps up
Router stats - Connection speed 40000 kbps down, 9997 kbps up - Line Attenuation 19.3 dB down, 0.0 dB up - Noise Margin 9.8 dB down, 9.9 dB up.


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Administrator MrSaffron
(staff) Mon 12-Nov-18 14:18:30
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Re: Noise margin increased (Sky FTTC)


[re: giggsy1977] [link to this post]
 
If there is more noise the margin will actually go down

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User giggsy1977
(member) Mon 12-Nov-18 14:42:47
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Re: Noise margin increased (Sky FTTC)


[re: MrSaffron] [link to this post]
 
Of course, makes sense as it's the margin I'm looking at. That's good to know then. Thanks again AndyPandy and MrSaffron. smile

BT Infinity 2 - Predicted speed 54.7Mbps down/15.7Mbps up. Actual speed 42Mbps down/4.5Mbps up...crazy Left BT as they were poor...
Now with Sky Fibre - 37.5Mbps down, 9.5Mbps up
Router stats - Connection speed 40000 kbps down, 9997 kbps up - Line Attenuation 19.3 dB down, 0.0 dB up - Noise Margin 9.8 dB down, 9.9 dB up.
Standard User candlerb
(member) Mon 12-Nov-18 15:08:56
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Re: Noise margin increased (Sky FTTC)


[re: giggsy1977] [link to this post]
 
And the inverse is true: if DLM decides to reduce your speed, the noise margin will go up.

When Sky raises the cap on your service, the noise margin will go down. DLM will likely increase your speed until the noise margin falls to 3dB (for a Huawei DSLAM anyway), unless your new cap is hit first.
Standard User giggsy1977
(member) Mon 12-Nov-18 15:13:03
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Re: Noise margin increased (Sky FTTC)


[re: candlerb] [link to this post]
 
Candlerb - I'm on a Huawei cabinet so seeing it drop to 3db would be good (assuming my line is capable of course). The adsl checker from BT indicates my postcode should get high sixties if it's not impacted (suspect mine might be though) and as I'm with Sky I can't use the phone number check for a more accurate assessment.

BT Infinity 2 - Predicted speed 54.7Mbps down/15.7Mbps up. Actual speed 42Mbps down/4.5Mbps up...crazy Left BT as they were poor...
Now with Sky Fibre - 37.5Mbps down, 9.5Mbps up
Router stats - Connection speed 40000 kbps down, 9997 kbps up - Line Attenuation 19.1 dB down, 0.0 dB up - Noise Margin 13.1 dB down, 10.10 dB up.
Standard User max360
(learned) Mon 12-Nov-18 17:02:04
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Re: Noise margin increased (Sky FTTC)


[re: giggsy1977] [link to this post]
 
Since my cabinet went live. I started on the 23dB noise margin, since more and more people started ordering the VDSL service, the noise margin now stands at: 10.7dB

Line stats:
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 35369 Kbps, Downstream rate = 95496 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 10.7 19.8
Attn(dB): 7.8 0.0
Pwr(dBm): 13.4 -8.2


ISP: PlusNet: Downstream rate = 79999 Kbps - Upstream rate = 19999 Kbps. Ping: 11ms.
Line Stats: Line attenuation Down: 7.8db Up: 8.7db

Stechford (CMSTE) Cab 24 - Funded Privately (Community Partnership).

Birmingham Fibre First Program: FTTP (CBT) installed on poles.

Website: http://www.stechford.online/
Standard User giggsy1977
(member) Mon 12-Nov-18 17:36:51
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Re: Noise margin increased (Sky FTTC)


[re: max360] [link to this post]
 
But you're lucky in that you have a very short line and your attainable speed is in excess of what the line will support. I have been on my cabinet for about 6 years, but within the last few months a second smaller Huawei cabinet appeared alongside it, so maybe that has something to do with my noise margin increase?

BT Infinity 2 - Predicted speed 54.7Mbps down/15.7Mbps up. Actual speed 42Mbps down/4.5Mbps up...crazy Left BT as they were poor...
Now with Sky Fibre - 37.5Mbps down, 9.5Mbps up
Router stats - Connection speed 40000 kbps down, 9997 kbps up - Line Attenuation 19.1 dB down, 0.0 dB up - Noise Margin 13.1 dB down, 10.10 dB up.
Administrator MrSaffron
(staff) Mon 12-Nov-18 17:54:27
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Re: Noise margin increased (Sky FTTC)


[re: giggsy1977] [link to this post]
 
Another cabinet with the prospect of more people with VDSL2 and thus more crosstalk would normally lead to lower noise margins

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
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