This topic

Mismatched max upload sync and low data rate on new connection?

busywait — Sat, 13 Feb 2021 12:12:42 GMT

Hello,

Back in Nov 2020 my Fibre 1 package became unreliable. The master faceplate was replaced and everything settled down. In Jan 2021 I ended my contract with BT (ported phone and broadband to Virgin Media cable), and then started a new contract for Fibre 2 and got a new Super Hub 2 router. Stats from the SH2 are below:

Although I am now on Fibre 2 the data rates are exactly what I used to get on Fibre 1. Am I right that I should be getting much closer to the maximum data rate numbers? Who at BT can I nudge to fix that?

Also, looking at the numbers that others are posting here, does my max upstream number look unusually low compared to the downstream? Is there anything that can be done to trade off down for up?

There is not yet any prediction for this line in the BT Wholesale Availability Checker:

Re: Mismatched max upload sync and low data rate on new connection?

imjolly — Sat, 13 Feb 2021 11:44:23 GMT

it looks from your hub stats that you are fibre 1 so can you check MYBT and package and see what that says you currently have

are you just connected as there are no vdsl estimates showing for your phone number

Re: Mismatched max upload sync and low data rate on new connection?

busywait — Sat, 13 Feb 2021 11:59:01 GMT

Thanks.

The MyBT web page says "Fibre 2" when I look at the "Your BT Broadband" button.

Yes it's a new connection (or at least, a new phone number via a 13-year-old wire in to my house) turned on yesterday.

I think by coincidence I've just had a phone call from BT customer services to finish off the set-up on this account. They suggested that perhaps the rate cap was to protect the line from errors, but are going to take a look at what's set in the account 😕

Re: Mismatched max upload sync and low data rate on new connection?

imjolly — Sat, 13 Feb 2021 12:06:27 GMT

if only set up yesterday then going to take a week or so before registers on openreach database and vdsl shows on dslchecker results

certainly looks like provisioned for fibre 1

Re: Mismatched max upload sync and low data rate on new connection?

busywait — Sat, 13 Feb 2021 12:07:56 GMT

Thank you 🙂

Do you/does anyone know if there's any way to sacrifice the downstream speed for better upstream?

Re: Mismatched max upload sync and low data rate on new connection?

Keith_Beddoe — Sat, 13 Feb 2021 12:14:03 GMT

@busywait wrote:
Thank you 🙂

Do you/does anyone know if there's any way to sacrifice the downstream speed for better upstream?

No, that is fixed by the VDSL profile, and cannot be changed.

Fibre 2 should be capable of up to 20Mbs upload connection speed.

Re: Mismatched max upload sync and low data rate on new connection?

Gary_C — Sat, 13 Feb 2021 12:17:58 GMT

No, you dont get the choice.
The cabinet negotiates (within any artificial cap imposed by your plan) the fastest connection with enough noise margin to stop errors.

Is there anyway people to check if his cabinet should negotiate 3db or 6db ? (is the g.inp thing fixed yet ?)

EDIT : just seen ECI and G.INP still doesnt work and was pulled again in August last year !

Re: Mismatched max upload sync and low data rate on new connection?

Gary_C — Sat, 13 Feb 2021 12:20:39 GMT

Quote

No, that is fixed by the VDSL profile, and cannot be changed.

Fibre 2 should be capable of up to 20Mbs upload connection speed.

But his max upload sync is less than 20mbs so he will never get that fast no matter what package surely ?

Re: Mismatched max upload sync and low data rate on new connection?

pippincp — Sat, 13 Feb 2021 12:21:09 GMT

ECI cab so G.INP may not be available.

Re: Mismatched max upload sync and low data rate on new connection?

Gary_C — Sat, 13 Feb 2021 12:23:07 GMT

So he might see a small increase in upload but the download is about as fast as it will go (ie 6db margin) ?

Re: Mismatched max upload sync and low data rate on new connection?

busywait — Sat, 13 Feb 2021 12:41:00 GMT

Thanks all

(Bing for G.INP seems to have a very relevant first hit: https://www.increasebroadbandspeed.co.uk/g.inp - thanks for mentioning it )

But because that's likely/possibly not in the cabinet that I'm served from I'll not get too excited.

As long as my connection floats up to the current technical limit, not an incorrect package limit, I'll be happy.

Is a 6dB noise margin the default target?

Re: Mismatched max upload sync and low data rate on new connection?

pippincp — Sat, 13 Feb 2021 14:49:40 GMT

Yes 6dB is target.

Re: Mismatched max upload sync and low data rate on new connection?

busywait — Sat, 13 Feb 2021 21:04:10 GMT

My final question I think ...

What is the maximum data rate quoted? Is it the data rate with 0dB noise margin??

Re: Mismatched max upload sync and low data rate on new connection?

bkehoe — Mon, 15 Feb 2021 10:42:33 GMT

No, it's the estimated maximum rate possible with the current SNR target. The default for up & down is 6dB but as low as 3dB can be used for downstream only on Huawei cabinets.
If interleaving is active on a line it distorts the maximum attainable figure though and will usually make it appear artificially high.