Am I on an 80/10 line?

[#1]

Is there anyway to check my line provision? I think I'm on an 80/10 provision rather than 80/20. My line and signal attenuation are relatively low for upload both at 11.2 and my sync speed is only 8.5mpbs with a solid noise margin of 6. I know I'm on 80 for download as my download sync is 58 but with a much higher line/signal attenuation. I checked my Plusnet account and it estimates I should get an upload speed of 18 (I'm not holding Plusnet to that it's more that it suggests I should be on a 20mbps provision for upload). Anyway for this to be checked?

[#2]

Have a look at your router status, if a Hub 2 it's Advanced settings, Technical Log. Specifically speeds and noise margin.

As a comparison I'm on a probably slightly better line than yours and it's sync'd at 64mbps/11.5mbps (so 80/20) with noise margin 5.0/3.1. Attenuation is about 11/19.

I don't think you get very near 20mbps upload except on very short/good lines.

[#3]

The figures above are from my router stats, 11.2 for my line and signal attenuation and 6 for my noise margin. I might be wrong but if the line is only sending out 10mpbs when it leaves the cabinet then I would get a proportion of that (hence the 8.5mbps I'm currently getting). I feel like with the attenuation and noise margin I should be getting above 10 if it was provisioned at 20?

[#4]

But what are the figures for data rate and maximum data rate? That will show what the carrier tones are capable of achieving.

If your line was capable of well over 10 upload but was limited to 10 it would run at 10 almost precisely and probably show excessive noise margin.

[#5]

I'm not sure that is how it works, if I maintain 80% of the signal when it leaves the cabinet on a line only sending out 10mbps it would be 8 on the router, if it is sending out 20mbps then it would sync at 16?

What you are suggesting is that if the line was capped at 10 but my line was capable of more then I would be syncing at 10 on the router but that would suggest that I would have maintained 100% of the signal which is impossible unless you are next to the cabinet?

My maximum data rate and data rate are both at 8.784.

[#6]

If your line was capable of "up to" 80/20, but had been provisioned on 80/10

then your line stats would look something like -

        Data Rate:    9.999 Mbps / 58123 Mbps 
Maximum Data Rate:   18.456 Mbps / 62786 Mbps

where the upload "Maximum Data Rate" would be noticeably higher than the "Data Rate"

AND your upload "Data Rate" would be as shown "9.999 Mbps" or "10.000 Mbps" rate limited by wrong provisioning.

[#7]

Do people on 40/10 lines show maximum data rates above these caps if either have the capacity to go higher?

I thought you lost a % of the signal as it travelled from the cabinet? So if you were provisioned a 40/10 line and you maintained 80% of the signal your sync speed might be 40*0.8=32 because the cabinet is only sending out 40mbps to begin with? If the line was raised to 80 would it not be 80*0.8=64? So although the line was capable of 64mbps on an 80 download provision it wouldn't show 40mbps on a 40 provision as that would imply it maintained 100% of the signal?

[#8]

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@JHarland wrote:

My maximum data rate and data rate are both at 8.784.

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That being the case, then you probably have internal wiring issues, either with phone extension wiring, or electrical noise anywhere along the landline wire from where it enters your house, all the way to the router.

Low broadband upload speeds are typically related to the lower frequency problems, such as an interfering phone, or mains interference, or plugging the router in to an extension socket, etc.

Have you tried plugging your router in to the TEST SOCKET behind the Master Socket faceplate using a short DSL cable ?

[#9]

I've taken the face plate off and have plugged directly into the test socket with a microfilter, no internal wiring can be involved in my setup

[#10]

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@JHarland wrote:

Do people on 40/10 lines show maximum data rates above these caps if either have the capacity to go higher?

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A modem provisioned on 40/10 might look something like this -

        Data Rate:    9.999 Mbps / 39.999 Mbps 
Maximum Data Rate:   18.456 Mbps / 62.786 Mbps

[#11]

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@JHarland wrote:

I thought you lost a % of the signal as it travelled from the cabinet? So if you were provisioned a 40/10 line and you maintained 80% of the signal your sync speed might be 40*0.8=32 because the cabinet is only sending out 40mbps to begin with? If the line was raised to 80 would it not be 80*0.8=64? So although the line was capable of 64mbps on an 80 download provision it wouldn't show 40mbps on a 40 provision as that would imply it maintained 100% of the signal?

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The signal isn't lost as it travels to/from the cabinet !,  99.999% that is transmitted will get received.

When the modem first communicates the cabinet, the modem and cabinet work out what the fastest data rate can be sent in each direction without loss of data. This becomes the "Data Rate".

The "Maximum Data Rate" is what might have been achieved if the DLM's target SNR margin could have been achieved.

If the negotiated "Data Rate" is higher than the provisioned rate, then the "Data Rate" gets set at the provisioned rate.

Once the link is established -

- the cabinet then sends data at the speed shown in the download "Data Rate"

- the home modem sends data at the speed shown in the upload "Data Rate"

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[#12]

So this is what chatgpt has stated (I'm not saying it's right I'm just relaying what it thinks)
…it strongly suggests you’re on an 80/10 profile, not 80/20.


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Why?

The maximum data rate is capped at 8.58 Mbps, and you're syncing exactly at that.

A 6 dB noise margin typically indicates you're close to the limit of your current profile — you're syncing at the cap.

If you were on an 80/20 profile, your maximum would likely be much higher than 8.58 Mbps unless there’s some line condition preventing it (which is uncommon for an attenuation of 11.3 dB).

[#13]

If everyone received almost 100% of the signal then surely distance from the cabinet would make no difference and everyone would have maximum speeds? My understanding was that as it travelled further from the cabinet the signal becomes weaker which is why people further from the cabinet have lower speeds?

[#14]

@JHarland wrote:
"Do people on 40/10 lines show maximum data rates above these caps if either have the capacity to go higher?"

Definitely not! That is what the cap does, it caps the line to the provisioned rate. I am on a 40/10 capped line and these are the figures from my Hub 2 router. (The SNR margin will be quite high)

Downstream sync speed: 39.999 Mbps
Upstream sync speed: 10 Mbps

Whereas, from the BT Broadband checker for my cabinet (interestingly measured today) the maximum speeds are shown as:-

Max Observed Downstream Speed: 78.25
Max Observed Upstream Speed: 20
Observed Date: 2025-08-05

[#15]

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@JHarland wrote:

If everyone received almost 100% of the signal then surely distance from the cabinet would make no difference and everyone would have maximum speeds? My understanding was that as it travelled further from the cabinet the signal becomes weaker which is why people further from the cabinet have lower speeds?

Almost 100% of the data (not signal) will will be received, when sent at the speed determined by the "Data Rate".

The "Data Rate" is calculated from the ratio of the wanted signal and the interfering noise.

Therefore because there is less signal on a long line, the ratio of that lower amount of signal compared to a relatively constant noise, results in a lower "Data Rate", compared to a higher "Data Rate" on a short line where the signal is higher.

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