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Fibre 80/20 speed expectations

RealAleMadrid
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Re: Fibre 80/20 speed expectations

@Gandalf  Don't bother testing my line, things have changed. I can only get full sync after a local area power cut and lost it when my house supply tripped out and the  modem lost power.☹️  I have capped my sync speed to 60Mbps now in an attempt to remove retransmission high, this has been known to work for some users.

Gandalf
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Re: Fibre 80/20 speed expectations

@RealAleMadrid Ah now that explains what I was seeing when I checked your line stats yesterday (On the back of this thread), I thought it was odd you only had a speed of around 60mbps. 

Fingers crossed for a speedy recovery to your speed (No pun intended)

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
Plusnet
ncd
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Registered: ‎05-08-2007

Re: Fibre 80/20 speed expectations

Hi @Gandalf,

Thanks for the reply.

In an earlier post you mentioned
The banding on your line is: "Downstream: 0.128M-80M with Retransmission (Low). Upstream: 0.128M-20M with no error protection" which shows you're on an open unrestricted banding.

Does this mean my banding has changed? What would cause retransmissions?

Looking on here https://windows.mouselike.org/be/index.asp?DoAction=BrasChecker with my land-line number it's showing a bRAS profile of 73.7.

Thanks,
N
Gandalf
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Re: Fibre 80/20 speed expectations

Hi @ncd There’s no restrictions on your sync speed however retransmission is going to cause a lower BRAS/IP profile which will affect your throughput. Retransmission is setting on a line handled by DLM, which is a form of error correction similar to interleaving. 

If you’re seeing the BRAS at 73.7mbps that’d make more sense and in line with what Kevin’s seeing as you’ve both got an 80mbps sync speed and retransmission enabled.

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
Plusnet
Kevin
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Re: Fibre 80/20 speed expectations

@ejs It's not a case of only just noticing it, I know it's been this way for a long time. Day to day use is fine, but it's one of those little niggling things that it "could be faster"  Smiley

So the question now is, why am I on retransmission high if my connection is good enough to give me a full 80Mb sync. Or is it the retransmission being high that is giving me the higher sync rate?

I suppose the only way to change this would be a DLM reset.

[Edit] But even with a PN profile of 73.6Mb I should still get higher test speeds than I do. Is this difference the static IP problem?

 

 

Kevin.
Gandalf
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Re: Fibre 80/20 speed expectations

@Kevin I wouldn't have thought retransmission high would be a direct cause for your 80mbps sync speed although it may be a contributing factor since it's a form of error correction it may be keeping some errors at bay.

Unfortunately we can only arrange a DLM reset if your sync speed is artificially restricted by a banding.

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
Plusnet
Gandalf
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Re: Fibre 80/20 speed expectations


@Kevin wrote:

[Edit] But even with a PN profile of 73.6Mb I should still get higher test speeds than I do. Is this difference the static IP problem?


Sorry I missed your edit earlier. To try to answer your question, if our profile on your account is 73.6mbps this seems to be in line with your 80mbps sync speed with retransmission high on and what your bRAS profile is reporting as.

You've said you're getting a throughput of 71mbps which is about right as you'd struggle to get a throughput that's spot on to the bRAS profile.

Our profile on your account will only affect your throughput if it's set below the bRAS profile of the line (and you have a static IP) which doesn't look to be the case here. 

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
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fwdlink
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Re: Fibre 80/20 speed expectations

Hi @Gandalf, sorry for delay, was away....Feel free to have a look at my line, one thing to note, my cabinet had an update in the last week and my line retrained and I see I'm now on rtx high too, grr.  I haven't touched my line, but thought of capping it to try and get rid of rtx high, but figured I better wait until I get a steer from you.  With rtx high, the IP profile @ 92% would be something like 73.59 correct?   If that is the case, then I'd view the throughput to be suspect.  Happy for your feedback

(UPDATED MY POST AS WAS ABLE TO SYNC AT FULL SPEED AGAIN)

NOW:

Sync Speed: 79999

IP Profile: 66.8 (From PN Dashboard, BTW not providing, but looks suspicious)

Throughput: 67Mbps

What You'd Expect: 71-73Mbps (Considering RTX High) otherwise 76Mbps as noted below on RTX low.

 

PRIOR (December):

Sync Speed: 79999

IP Profile: 70.61

Throughput: 67Mbps

What You'd Expect: 76Mbps (3+yrs until October 2019)

 

Gandalf
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Re: Fibre 80/20 speed expectations

Hi @fwdlink No problem, running a test down your line I can see the current BRAS profile rate is 72.7mbps which is about what I'd expect for a line with high retransmission on and a throughput of 67mbps is about right for that. I think the profile we're reporting in your account at 66.8mbps is just a red herring.

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
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fwdlink
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Re: Fibre 80/20 speed expectations

Hi @Gandalf , that's reassuring, I've capped my line to try and get rtx high off, will report back once I've got it off and tested.

Gandalf
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Re: Fibre 80/20 speed expectations

Cool, no problem.

Let us know how it goes. Smiley

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
Plusnet
ncd
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Re: Fibre 80/20 speed expectations

Hi @Gandalf ,

 

As always thanks for the reply. Apologies for the delay in replying, I've not had a chance to respond until now.


@Gandalf wrote:

Thanks @ncd looking at your BRAS profile this is currently at 75.9mbps (We've incorrectly reported that at 78mbps) and while I believe it should be 77.36mbps, I suspect that may be caused by retransmission being enabled on your line.

Based on the BRAS of 75.9mbps a throughput of 71mbps is about right and isn't far off the mark to be honest.


When you say retransmission enabled on my line you mean I'm on retransmission high as a result of DLM? What can I do to help this adjust back?

ncd
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Re: Fibre 80/20 speed expectations

Hi @fwdlink  - mind me asking how you 'capped my line' ?

Gandalf
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Re: Fibre 80/20 speed expectations

As far as I remember it was retransmission low. I can't give any advice on how to influence DLM to remove this apart from allowing more time I'm afraid however RealAleMadrid and fwdlink seem to think that capping the line speed may help if your router offers this functionality. 

For the relatively small loss in speed caused by retransmission you'd have to weigh up whether it's worth the hassle. Or at least that's my personal view. Smiley

From 31st October 2022, I no longer have a regular presence here as I’ve moved on to a new role.
Anoush Mortazavi
Plusnet
fwdlink
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Re: Fibre 80/20 speed expectations

@Gandalf So my line is back to stats I had prior to all this issue back in October, and it looks like I'm on RTX Low again...

I've tested my line and I'm now maxing out at 71 Mbps versus the old 67 on Rtx High, having said that, looking at my stats from October I was getting ~76Mbps speedtests on an sync of 80 with same stats as I have now.

Please can you have a look at my line and see if you note RTX Low as well?  If looks normal would you then add my line to your list to pass on for review please.

Current Sync: 79999

IP Profile: 73.7