Hilariously dismal 'upgrade' offer

[#1]

@Dan_the_Van would you mind checking the Btw test  for your observed speed ?

[#2]

@MisterW 

[#3]

@Dan_the_Van thanks. I'm going to let @Gandalf explain the 66-73 estimate from an 80 Mb observed maximum speed then ?

[#4]

I would also be interested in the explanation for this.

As we live only 50 (cable) metres from the cabinet, our line also syncs at 80/20, (Max data rate approx 105/35), reliably - it stays connected for weeks on end, yet our estimated speed is also given as 66-73.

[#5]

@MisterW 

I have a stable line with the Hub Two uptime being 230 days, occasional DSL or PPPoE disconnects, max around 60 days currently 22 days

Some of the DSL disconnects are caused by a grumpy Master Socket 5C with a MK4 faceplate.

Line stats

Data rate:18.267 Mbps / 79.999 Mbps

Maximum data rate:17.606 Mbps / 89.386 Mbps

Noise margin:4.5 / 4.8

Line attenuation:6.3 / 11.3

Signal attenuation:6.2 / 12.0

I have a static IP Address 80.229.xxx.xxx

The last contract renewal email from March 2022

Unlimited Fibre Extra has an average speed of 66Mb download and 18Mb upload.
At peak times, we estimate that you'll get the following speeds on your line:
Download: 64 - 72Mb
Upload: 13 - 15Mb

Minimum Guaranteed Speed: 58.3Mb.

Seems the profile is marked down to make it more stable, but the above speeds are more than enough for my house hold needs.

[#6]

"Data rate:18.267 Mbps / 79.999 Mbps

Maximum data rate:17.606 Mbps / 89.386 Mbps"

I thought that the "Maximum Data Rate" is what the line could sync at, barring any contractual cap, and the "Data Rate" was what the router actually syncs at - leaving a safety margin to maintain stability?

In this example though, the Data Rate is higher than the Maximum Data Rate?

[#7]

As my line is very stable I have no need to look at the Technical log but yes Data rate and Maximum data rate readings do look odd. I just check the Status to see if there has been an overnight disconnect.

[#8]

I thought that the "Maximum Data Rate" is what the line could sync at, barring any contractual cap, and the "Data Rate" was what the router actually syncs at - leaving a safety margin to maintain stability?

I believe (but dont know for sure) that the Maximum data rate is what its calculated (by the router/dslam) that the line should achieve at the 'normal' target SNR margin of 6db. If the line is actually running at a target SNR lower than 6db then the sync COULD be above the Max

[#9]

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@MisterW wrote:

I believe (but dont know for sure) that the Maximum data rate is what its calculated (by the router/dslam) that the line should achieve at the 'normal' target SNR margin of 6db.

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Having had connections where the 'target SNR' has been 3dB, 6dB, and 9dB,  I'm pretty sure that the maximum/attainable data rate is an indication of the speed that would be likely reached if DLM's current SNR target was achieved, therefore I don't think this number always relates to a 6dB target SNR (but in practice does for most people).

Below is my most extreme example of actual modem sync being MUCH higher than the calculated attainable sync.

The DLM target SNR was 3dB, my line was happily running at 75.89Mbps with minimal errors, but due to bad weather conditions the modem's actual SNR margin had dropped below zero (to negative 4dB), and the "DS Attainable Rate" had correspondingly dropped to 55.78Mbps.  My Vigor 130 modem is REALLY good at hanging on to it's sync through storms and overnight margin fades,  BUT if it had lost sync I wouldn't have much doubt that it would have reconnected around 55Mbps.