Help with FTTC

Hi all,

I have recently binned the Sky package, including broadband and moved to Onestream. Despite being on a relatively new build development I don't have fibre and only have FTTC unfortunately.

Sky was wired to a slave socket in the lounge and ceased last week. This week I swapped my master socket in the study to a 5C with mk4 faceplate and disconnected any internal extensions from the wiring in anticipation of the new service going live today. My understanding was that the line would stabilise over the next 10 days, however it has synched to exactly the same as the Sky line and has not moved.

|Upstream |Downstream
Current Rate (kbps) |9997 |34999
Max Rate (kbps) |10141 |47603
SNR Margin (dB) |6.2 |6.9
Line Attenuation (dB) |3.8 |16.9
Errors (pkts) |1 |0

BT Wholesale address checker tells me:

Downstream Line Rate(Mbps)
VDSL Range A (Clean) 53.2 (High) 35 (Low)
VDSL Range B (Impacted) 52.1 (High) 35 (Low)

Upstream Line Rate (Mbps)
VDSL Range A (Clean) 9 (High) 6.3 (Low)
VDSL Range B (Impacted) 8.9 (High) 6 (Low)

Downstream Handback
Threshold(Mbps)
VDSL Range A (Clean) 32.4
VDSL Range B (Impacted) 30

Am I missing something - shouldn't I be getting faster speeds?

Thanks.

Give it time …

In reply to a post by Zarjaz:

Give it time …

+1

Looking at the stats I'm wondering if there has been a glitch in the changeover and the new connection is capped at 35Mb. A connection rate of 34,999 at 6.9dB attenuation when the max attainable is 47603 doesn't ring true to me.

Edited by GonePostal (Thu 01-Jun-23 15:15:49)

In reply to a post by GonePostal:

Looking at the stats I'm wondering if there has been a glitch in the changeover and the new connection is capped at 35Mb. A connection rate of 34,999 at 6.9dB attenuation when the max attainable is 47603 doesn't ring true to me.

You may be right but I suspect the OP won't get anywhere with their ISP until at least 10 days have past so they do need to be patient.

Thanks for the advice all. I'll give it 10 days before contacting Onestream


My Sky speed wasn't meant to be capped at 35Mb, it was their "superfast" offering. - I wonder if its been artificially capped all along!

In reply to a post by FTTCSux:

Thanks for the advice all. I'll give it 10 days before contacting Onestream


My Sky speed wasn't meant to be capped at 35Mb, it was their "superfast" offering. - I wonder if its been artificially capped all along!

On their Superfast offering, Sky will provision lines on 40/10 if they deem it is not capable of at least 59 Mbps.

I had the same problem with Sky because the Openreach checker indicated my line supported a max of 56 Mbps and they would wouldn't put me on 80/20.

In reply to a post by FTTCSux:

My understanding was that the line would stabilise over the next 10 days, however it has synched to exactly the same as the Sky line and has not moved.

Well, it *is* the same line, so syncing at exactly the same speed is not entirely unexpected. The changes you made to disconnect the extensions and move the router to the master socket might not have made any significant difference - given the distance you are from the cabinet, another 10 metres is not a big deal.

It looks like DLM has chosen a SNR target of 6dB. Depending on what type of DSLAM you are connected to, and if the line remains stable, DLM may decide to move you to a 3dB SNR target which will bump up your speed. However this can take several weeks or even months.

In reply to a post by FTTCSux:

Am I missing something - shouldn't I be getting faster speeds?

Not really. The speed you are getting is within the range of predicted speeds, and indeed your upstream is slightly above the predicted range, so no, there's no reason you should expect anything faster.

There are a bunch of issues with FTTC, including:

- weather / time of year. When I moved to this house in 2016, I was getting around 35M in winter but 30M in summer. (Other people have reported it going the other way round).

- crosstalk from adjacent users. As more people migrate from ADSL to FTTC, crosstalk gets worse and reduces speeds for everyone. By the time I left FTTC in 2019, I was getting, at best, 30M in summer and 25M in winter.
https://www.increasebroadbandspeed.co.uk/2014/vector...

In reply to a post by FTTCSux:

Am I missing something - shouldn't I be getting faster speeds?

Your line is provisioned by Sky at 40/10 so it cannot go above that.
However the DLM has capped your line at 35/10 so you're getting a little less than what's possible.

Some migrations don't fully reset the DLM meaning banding can transfer from 1 provider to another but that's only for specific migrations and not usually the case.

It's possible the DLM has applied the banding since switching particularly if there was multiple resyncs from rebooting modems and moving the NTE etc.

You either need to wait for the DLM to remove the banding on its own (which isn't even guaranteed to happen or can take a long time) or convince Sky to perform a DLM reset.

The line looks like it might be interleaved due to the max rate being much higher than the sync speed but with only a 6.9dB SNRM.
Interleaving exaggerates the max data rate.

If the line is interleaved then I estimate you would sync around 38-39Mb/s if it wasn't capped by the DLM.

In reply to a post by j0hn83:

In reply to a post by FTTCSux:

Am I missing something - shouldn't I be getting faster speeds?

Your line is provisioned by Sky at 40/10 so it cannot go above that.
However the DLM has capped your line at 35/10 so you're getting a little less than what's possible.

Some migrations don't fully reset the DLM meaning banding can transfer from 1 provider to another but that's only for specific migrations and not usually the case.

It's possible the DLM has applied the banding since switching particularly if there was multiple resyncs from rebooting modems and moving the NTE etc.

You either need to wait for the DLM to remove the banding on its own (which isn't even guaranteed to happen or can take a long time) or convince Sky to perform a DLM reset.

The line looks like it might be interleaved due to the max rate being much higher than the sync speed but with only a 6.9dB SNRM.
Interleaving exaggerates the max data rate.

If the line is interleaved then I estimate you would sync around 38-39Mb/s if it wasn't capped by the DLM.

Thanks for the info. For clarity, I was with Sky on their Superfast (Not Superfast 35) and have moved to Onestream on their Fibre 55 package. My sync speed on Sky was always 34999 as I assumed this was the line capacity since moving in. Now on Onestream I realise that this might have been incorrectly capped by Sky as I'm now getting 8494 up and 37568 down, whilst the max rate today is 9954 up and 48423 down - much closer to the Openreach address check speeds.