Infinity 4 Throttling and Congestion

Moved to a new place this week that has FTTP - yippee!

Despite being a new build though it only has up to Infinity 4, not Ultrafast 1 or 2.

The engineer was meant to arrive this week to install it but - surprise surprise - was a no show. BT called later in the day to say it 'fell through the system', and couldn't even reschedule because the appointment booker wasn't working. Anyway...

I connected the BT Hub myself and surprisingly it works. Not sure why an engineer was needed. Over the first 24 hours the speeds steadily increased from 20 Mbps to 50 to 100 and then finally to a fairly consistent 240 Mbps and up. Uploads are a solid 30 Mbps despite Infinity 4 in theory being only 20.

But since then the speeds have been all over the place and the speed graphs scream to me "throttling!". They look just like I used to get from Virgin cable in a horribly congested street. Screenshots: https://cl.ly/0j3E0w2E0q0g https://cl.ly/2L112N3C3T3Z

In the evenings I frequently can't do better than 50 Meg - barely enough for 4K HDR movies from iTunes.

The building is a large apartment block. Probably 300+ units. Is this just the reality of FTTP? Extremely disappointing if so.

(Yes I'll get BT on the case but at the moment they can't even figure out how to get an engineer to show up!)

Edited by deleted (Sat 12-May-18 11:29:47)

I believe Infinity 4 is 330/30.

How are you connecting to run these tests, if by wifi then this isn't a good/accurate method.

Can you run some trace routes to see where this throttling and congestion is occurring ?

Edited by Zarjaz (Sat 12-May-18 11:26:52)

That's right, in theory it is profiled at 330/30 but they sell it as 300/20.

The results are the same whether on ac Wi-Fi, or connected directly via Ethernet (Cat 5e and better), whether using the BT Hub as a router, or replacing it with my Linksys Velop (which I only did to see if it would fix the issue - though I'd prefer to keep it anyway, can't stand BT Hubs). It always bursts to near the expected speed and then appears to throttle like hell.

[The Velop also has the ability to run speedtest.net tests itself (i.e. cabled speed to the router) and the results are just the same. I wish it was just Wi-Fi issues!]

I thought FTTP was meant to be rock solid. I'd prefer 100 megs reliably than 50-250 based on the time of day

Currently using the Velop as you can see in the below trace route (which doesn't seem to indicate a problem) but the problems persist whatever I use.

I've rebooted the modem.

Text

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 2627 2829 3031 3233 3435 3637 3839 4041 4243

Traceroute has started�  traceroute to 8.8.8.8 (8.8.8.8), 64 hops max, 72 byte packets  1  linksys08769 (192.168.1.1)  3.739 ms  2.043 ms  1.273 ms 2  * * *  3  31.55.186.197 (31.55.186.197)  7.265 ms  3.705 ms  3.889 ms 4  31.55.186.204 (31.55.186.204)  4.571 ms  4.597 ms  5.119 ms  5  195.99.127.90 (195.99.127.90)  6.030 ms  4.803 ms  5.057 ms 6  peer2-et-2-3-0.redbus.ukcore.bt.net (62.172.103.37)  5.878 ms  6.005 ms  7.408 ms  7  109.159.253.93 (109.159.253.93)  6.096 ms  7.084 ms  5.943 ms 8  * * *  9  64.233.175.154 (64.233.175.154)  7.743 ms  6.104 ms  5.191 ms10  108.170.230.157 (108.170.230.157)  5.964 ms  6.593 ms  6.012 ms 11  google-public-dns-a.google.com (8.8.8.8)  5.013 ms  4.829 ms  4.828 ms   Traceroute has started�  traceroute to 8.8.4.4 (8.8.4.4), 64 hops max, 72 byte packets  1  linksys08769 (192.168.1.1)  2.457 ms  1.158 ms  2.165 ms 2  * * *  3  31.55.186.193 (31.55.186.193)  6.477 ms  4.649 ms  5.000 ms 4  31.55.186.212 (31.55.186.212)  5.032 ms  4.913 ms  4.495 ms  5  host213-121-192-52.ukcore.bt.net (213.121.192.52)  4.672 ms  6.087 ms  4.804 ms 6  peer7-et-3-0-0.telehouse.ukcore.bt.net (62.6.201.212)  4.761 ms  4.869 ms  5.289 ms  7  109.159.253.185 (109.159.253.185)  4.867 ms  6.060 ms  4.933 ms 8  * * *  9  216.239.46.12 (216.239.46.12)  9.057 ms  8.240 ms  6.194 ms10  108.170.230.163 (108.170.230.163)  7.562 ms  6.726 ms  6.530 ms 11  google-public-dns-b.google.com (8.8.4.4)  5.086 ms  5.788 ms  6.357 ms   Traceroute has started�  traceroute to 1.1.1.1 (1.1.1.1), 64 hops max, 72 byte packets  1  linksys08769 (192.168.1.1)  4.839 ms  5.170 ms  7.273 ms 2  * * *  3  31.55.186.197 (31.55.186.197)  5.448 ms  3.782 ms  3.555 ms 4  31.55.186.232 (31.55.186.232)  4.847 ms  3.617 ms  4.635 ms  5  195.99.127.108 (195.99.127.108)  4.813 ms  4.579 ms  4.872 ms 6  peer5-hu0-12-0-0.telehouse.ukcore.bt.net (213.121.193.185)  6.112 ms  4.968 ms  6.081 ms  7  195.99.126.1 (195.99.126.1)  9.696 ms  4.622 ms  6.761 ms 8  1dot1dot1dot1.cloudflare-dns.com (1.1.1.1)  4.184 ms  4.432 ms  4.879 ms

Here's an even better screenshot of the current throttling: https://cl.ly/2k1K12272H3Q

OK, so you seem to have ruled the usual suspects ...

Have you spoken to any of your neighbours to see if they are experiencing similar issues ?

In reply to a post by Zarjaz:

I believe Infinity 4 is 330/30.

I think its 300Mbps down and 20Mbps up, so BT told me.

Paul

The neighbours are not the technical type... it's only obsessives like me who verify the speeds!

That said I did see a chap a few floors down picking up an Intel processor from the mail room - he seems like the type that would keep an eye on these things, hopefully I will bump into him again.

In the meantime, does FTTP work the same as FTTC in terms of profiling? Will turning the modem off (which you can only do by pulling the plug due to the battery backup) be detected as a line error and cause it to profile down?

With the speeds hovering at around 150 it could be that I've been profiled at 152 Mbps, i.e. Infinity 3.

I would have a look what the profile is however the BT Wholesale checker has no trace of an FTTP connection at my address (or any address in the building for that matter). Useless.

What exchange are you on, when we were on Infinity 4 we were getting ~310Mbps down and a solid 32Mbps up.

Ours only went down in the evenings where it would normally drop down to about 200Mbps (around 6pm to 10pm), only once did it drop down to 45Mbps.

This time of the day you should be getting your max speed or very close to it.

I just did a SpeedOfMe Test and got >> this <<<.

Also it shouldn't be the case of it starting at 20Mbps then 50, 100 and then 240, something isn't right.

The sad thing is BT won't class this as an issue until it goes below 45Mbps (on Infinity 4) when they do their checks.

Paul

According to the dslchecker.bt.com address checker I'm on the Mile End exchange but I can't check using the telephone number checker as the number still isn't on the system.

In reply to a post by Brookzy:

In the meantime, does FTTP work the same as FTTC in terms of profiling? Will turning the modem off (which you can only do by pulling the plug due to the battery backup) be detected as a line error and cause it to profile down?

No, when you connect you connect up at the speed that you are paying for, however due to congestion you might not get your speed.

It might not be this, but you never know, but your fibre might have a bad joint on it, not too sure if a bad joint causes latency issues (due to your latency seems fine), but I think it does cause speed issues.

Paul

In reply to a post by Brookzy:

According to the dslchecker.bt.com address checker I'm on the Mile End exchange but I can't check using the telephone number checker as the number still isn't on the system.

Ah, your down the road from me, I am on Ilford Central.

Did your phone get moved over to fibre as well, i.e. on the ONT is the TEL1 light on?
If so you have FVA (Fibre Voice Access) and no checker will know your number due to its no longer a PSTN number.

Our phone number is the same due to it also being on FVA.

BTW what cabinet did it say you was on?

Paul

Edited by PaulKirby (Sat 12-May-18 12:18:57)

Yes it's an FVA line (and always was, i.e. it wasn't moved, it's a brand new building.)

The ping is absolutely fine. I think BT just cheaped out on the provision to the building and there is mega congestion going on. Especially if they consider 45+ to be fine.

In reply to a post by Brookzy:

Yes it's an FVA line (and always was, i.e. it wasn't moved, it's a brand new building.)

The ping is absolutely fine. I think BT just cheaped out on the provision to the building and there is mega congestion going on. Especially if they consider 45+ to be fine.

Have you tried doing a speed test on BT's Site?
Just log into your MyBT section and do a Speed Test, it might be your exchange is congested.

Paul

I try to do the BT test and I get "We've completed our checks and it looks like you're not connected to the internet." Hahaha

I don't really know how the backend works but it seems feasible to me that the capacity to the building just can't cope, hence the time of day-linked slowdowns.

What do speedtest.net and TBB speedtester give you? I wouldn't read too much into speedof.me results they can be off by quite a bit on my 330/30 FTTP line.

Btw officially BT Residential no longer sell Infinity 4 (330/30) to new customers, their highest speed tier is now called Ultra Fast 2 (330/50). If the BT/Openreach checker says you can get 330/50 then BT *should* be able to re-grade your line you once they sort out their internal systems. I think PaulKirby did the same recently, he might be able to put you into touch with the correct BT dept who sorted this out for him.

Thanks for the info. Typical BT mess up then. Because when I ordered I kept trying to get Ultrafast 2. I called back three times and asked different people for it, all via the dedicated FTTP number. They were all adamant that Ultrafast was not available and I could only get Infinity 4 - a service not even shown on the website. I even quoted the results of the DSL checker to them.

Both those sites give exactly the same results but without the graph which is helpful for seeing the throttling/congestion.

I'll chase BT eventually but right now I'm still waiting for a call back for an engineer appointment to be made. And to be honest I have no energy to do the whole "turn your box off and on!" typical troubleshooting rubbish with a call centre person.

In reply to a post by baby_frogmella:

What do speedtest.net and TBB speedtester give you? I wouldn't read too much into speedof.me results they can be off by quite a bit on my 330/30 FTTP line.

I don't normally use SpeedOfMe, but did due to the OP used it, it did seem about right for me.
I normally use both the TBB Speedtest and speedtest.net when testing.

In reply to a post by baby_frogmella:

Btw officially BT Residential no longer sell Infinity 4 (330/30) to new customers, their highest speed tier is now called Ultra Fast 2 (330/50).

BT still sell Infinity to new customers where Ultrafast 1 & 2 are not yet available to them.

In reply to a post by baby_frogmella:

If the BT/Openreach checker says you can get 330/50 then BT *should* be able to re-grade your line you once they sort out their internal systems. I think PaulKirby did the same recently, he might be able to put you into touch with the correct BT dept who sorted this out for him.

If the OP sees the something like >> this << then they should be able to get Ultrafast 2 with BT.

As for pointing them to the right department at BT, I spoke to Sales->Sales->FTTP Team->Sales (higher level) who passed it off to the Offline Team, which a week later I spoke to Sales who processed the upgrade.

If Ultrafast 1 & 2 are available to the OP and there is no issues in the upgrade then normal Sales will be fine.

Paul

In reply to a post by Brookzy:

I try to do the BT test and I get "We've completed our checks and it looks like you're not connected to the internet." Hahaha

I don't really know how the backend works but it seems feasible to me that the capacity to the building just can't cope, hence the time of day-linked slowdowns.

I wouldn't be surprised there.

Paul

I see: https://cl.ly/3e3M0U0s1H3j

Yet, as I mentioned above, I could not order Ultrafast services despite pointing to that data on the phone.

(I initially tried to place an order for Ultrafast 2 online but that failed hence I called.)

In reply to a post by Brookzy:

Thanks for the info. Typical BT mess up then. Because when I ordered I kept trying to get Ultrafast 2. I called back three times and asked different people for it, all via the dedicated FTTP number. They were all adamant that Ultrafast was not available and I could only get Infinity 4 - a service not even shown on the website. I even quoted the results of the DSL checker to them.

Both those sites give exactly the same results but without the graph which is helpful for seeing the throttling/congestion.

I'll chase BT eventually but right now I'm still waiting for a call back for an engineer appointment to be made. And to be honest I have no energy to do the whole "turn your box off and on!" typical troubleshooting rubbish with a call centre person.

When I phone BT I call 0800 587 4787 I was also told that Ultrafast wasn't available to me even though my neighbours could order it and we were all using the same hardware, also BTOR and checkers stated it was available, but BT said it wasn't, then a month later I was.

A screenshot of the DSL Checker (http://www.dslchecker.bt.com/) would be nice, but remember to remove your address part leaving Exchange name and cabinet number viewable.

BT do hope people give up, I never give up and I think BT are aware of this LOL.

The best thing is to always be polite but be firm when speaking to BT, nobody likes being spoken to in a rude and raised voice.

TBH, I think BT's systems are rubbish and need to be replaced with newer software due to from what I have heard, if you are already on Infinity 4 with FVA you will have issues, this is due to Infinity is / was their highest tier and the system gets confused when trying to order Ultrafast 1 or 2 also having FVA confuses the system more due to it thinks you don't have a phone line.

Paul

In reply to a post by Brookzy:

I see: https://cl.ly/3e3M0U0s1H3j

Yet, as I mentioned above, I could not order Ultrafast services despite pointing to that data on the phone.

(I initially tried to place an order for Ultrafast 2 online but that failed hence I called.)

Ok, so you have no copper line at all, and you "CAN" get Ultrafast and that your Fibre uses the new connectorized connections.

I had to wait for a month after I was aware I could get Ultrafast, their system that sales use might just need to get the update that its available, BT's System is very slow to update, even when other providers shows those speeds available with them.

I am a very technical person so I was to the point, I also get all the information ready before the phone call with BT so that they cannot use excuses etc.

Try sending the whole dsl checker to BTOR on Twitter via a DM (NOT A TWEET) and ask them if their system shows that speed Down and Up is available to your address.

Once you have that along with a full screenshot from the DSL Checker explain to BT that their Wholesale Checker shows its available along with "their supplier", BT will say they system says its not, but say you would like to be put on the waiting list for Ultrafast and check up every week or two.

But for your speed issues I would just wait a week for them to get back to you or for their engineer(s) to arrive, if still no joy after a week I would phone BT back up for an update.

Also remain calm and be polite to them.

Paul

The tester at https://www.thinkbroadband.com/speedtest is useful as the two tests and any difference can tell people something. Speedofme can look a little odd as the initial tests are it trying to determine the file size to use for later testing

e.g. if the tbbx1 is a lot slower at peak times compared to the 1am to 8am period then congestion is most likely.

There is the urban myth that full fibre has no slow downs and while true for the connection speed, the shared nature of the bandwidth at some point in the network means things can slow down.

The local segment of fibre has 2.5 Gbps of capacity shared between something like 32 to 64 lines, so congestion there is pretty unlikely more likely this is at the exchange where data is handed over from Openreach to the BT Wholesale network which BT Consumer use.

Nah, a bad Splice would cause intermittent loss of service.

In reply to a post by Zarjaz:

Nah, a bad Splice would cause intermittent loss of service.

Wasn't too sure, its been +25 odd years since I have played with fibre, so maybe things have changed.

I know back then we saw data errors when we started to increase the speed when using a badly joint fibre.
But back then all we had was a very very fine grit sandpaper, and Eye Piece and some washing up liquid lol.

The reason that I thought it was a bad joint was where Pings / Tracing etc are not high speed as like downloading etc.

But ok, fair enough.

Paul

The only last thing I can think of is the grey box on the wall where the connectorised fibre comes from is a bit wobbly. Anyone know what�s inside? Does the cable come in as-is or is there a socket inside it that the optical cable plugs into?

It could be that that connection is dirty/loose.

In reply to a post by Brookzy:

The only last thing I can think of is the grey box on the wall where the connectorised fibre comes from is a bit wobbly. Anyone know what�s inside? Does the cable come in as-is or is there a socket inside it that the optical cable plugs into?

It could be that that connection is dirty/loose.

Does it look like one of >> these << ?

If so then its your CSP (Customer Splice Point) Box.

Paul

It could be that that connection is dirty/loose.

No it is most definitely not that.

BT don't throttle either. It's congestion.

Openreach FTTP is GPON, shared between upto 32 lines.
Someone else can do the maths, but if all your neighbours are Fibre only premises then it's congestion you will have to get used to and live with.
Changing ISP also won't help.

Connectorised don't got no CSP Paul.

Since I�m rarely getting more than 150 Mbps I am considering asking to downgrade to Infinity 3, but if I do that will my congested speeds suffer further? (E.g. if I�m getting 100 Mbps during congestion on a 300 Mbps profile, would that reduce to say 50 Mbps under a 152 Mbps profile?)

Re the grey box - it is connectorised but the grey box does look like the one linked above, albeit with only one cable coming out of it and indoors.

In reply to a post by Zarjaz:

Connectorised don't got no CSP Paul.

I know, but where the OP spoke about a grey box I was thinking maybe it wasn't using Connectorised.

Paul

In reply to a post by Brookzy:

Re the grey box - it is connectorised but the grey box does look like the one linked above, albeit with only one cable coming out of it and indoors.

Any chance in a photo of it?

Paul

No they wouldn't suffer further.

If you have a 300Mb package but get 50Mb at peak,
you would still get 50Mb at peak on the 80Mb package.

Yes: https://cl.ly/31042m0i0s1S and https://cl.ly/2e0K272X3g1w

(It's in a cupboard hence the weird camera angle.)

Looks like a customer splice point, with a short run of fibre to the ONT which of course has a connector on the end of it.

Full connectorised installs don't have the CSP since no need for one

I see, thanks for the info.

So now we�re in the peak of the peak period the speed�s dropped to 45 Mbps. Completely unacceptable IMO. And I thought Virgin were bad...

So not connectorised at all then ......

... and now it seems you were correct

In reply to a post by Zarjaz:

So not connectorised at all then ......

That's what I thought, we was only going by what the Wholesale checker said, i.e. 1 Stage Install, which normally means connectorised.

Paul

In reply to a post by Zarjaz:

... and now it seems you were correct

It was a lucky guess, I also thought it was using connectorised cables.

Paul

Apologies, I thought connectorised just meant it had the green connector on the end.

30 megs now, ridiculous. Good job I decided to hold off ordering a 4K TV until my internet was sorted.

All pre-wired and fitted, whilst the flats were being built.

On FTTP, Congestion can happen in 2 places: on the PON, shared with 32 other premises, and on the backhaul that your connection is part of.

If the problem is in the backhaul:
The gradual ramp-up of speeds when you first connected are an indicator of congestion in the backhaul pipe, with its capacity being increased incrementally as software systems identified it was overloaded.

Perhaps it is overloaded beyond the point that software can improve anything. Perhaps it needs human intervention to rebalance subscribers... Have you talked to anyone at the ISP (BT Retail) yet?

Or perhaps the systems don't consider you in need of rebalance because your data doesn't officially exist yet.

If the problem is in the PON:
2.5Gbps shared amongst 32 premises should nicely invoke Openreach's congestion mechanism, which means you should never get below 75ish Mbps each. And that would require all 32 to both subscribe to infinity 3 or 4, and all 32 to try to max it out simultaneously.

I don't believe that...

Thank you for your insight.

In the last few minutes I've gained access to the building's Facebook group and it appears internet is completely out on a few floors, and someone reports being on the 50th day without a connection. So I guess I should count myself lucky - and that there is a much bigger issue here. And historically there were far more widespread reports of outages. And images of many Openreach vans outside. And petitions for Hyperoptic to be allowed to install.

I will contact BT but at the moment I am still waiting for them to contact me about the engineer no-show.

If there were large outages is it conceivable that there is reduced capacity and more than 32 people sharing the 2.5 Gbps while repairs happen?

Well here is something... I put my number into the service status checker to see if there were any reported issues and it appears there is an open fault report in relation to the connection which was opened on Friday - the day the engineer was meant to show up but no-showed. I haven't contacted them about this at all nor have I received any contact about that fault. And it doesn't show up on the My BT page.

Maybe they're onto it already!

Screenshot: https://cl.ly/37293Y0X030b

In reply to a post by WWWombat:

On FTTP, Congestion can happen in 2 places: on the PON, shared with 32 other premises, and on the backhaul that your connection is part of.

If the problem is in the backhaul:
The gradual ramp-up of speeds when you first connected are an indicator of congestion in the backhaul pipe, with its capacity being increased incrementally as software systems identified it was overloaded.

Perhaps it is overloaded beyond the point that software can improve anything. Perhaps it needs human intervention to rebalance subscribers... Have you talked to anyone at the ISP (BT Retail) yet?

Or perhaps the systems don't consider you in need of rebalance because your data doesn't officially exist yet.

If the problem is in the PON:
2.5Gbps shared amongst 32 premises should nicely invoke Openreach's congestion mechanism, which means you should never get below 75ish Mbps each. And that would require all 32 to both subscribe to infinity 3 or 4, and all 32 to try to max it out simultaneously.

I don't believe that...

I had a speed drop when I was on Infinity 4 a while back when my speed dropped down to about 45Mbps, so I phoned BT but was told its not classed as a fault until it dropped below 40Mbps, so I gave a huge moan and was moved (their words) and it was fine.

But yeah, for the connection to drop down as low as the OP it wouldn't be the 1st place you said, I also worked this out to the lowest you would get to the exchange would be 78.125Mbps and like you said all 32 connections would also have to have Infinity 4 and hammering their connection, which is very unlikely indeed.

So what bandwidth is being used for lines on Ultrafast 2 due to we have a guaranteed minimum speed of 100Mbps, so they must up the hardware speed because they cannot reduce the 32 way split.

I know my connection suffers with speed drops in the evenings and over the weekends show here where you can see that the single threaded has issues getting the full speed, where as the multi threaded has no issues.



But that is fine if I wanted to download a large file I could just split them up into several files and then download them all at the same time.

TBH I think the OP's issues are between the Exchange and BT's Network at fault here.

Paul

Edited by PaulKirby (Sun 13-May-18 02:11:44)

In reply to a post by Brookzy:

Thank you for your insight.

In the last few minutes I've gained access to the building's Facebook group and it appears internet is completely out on a few floors, and someone reports being on the 50th day without a connection. So I guess I should count myself lucky - and that there is a much bigger issue here. And historically there were far more widespread reports of outages. And images of many Openreach vans outside. And petitions for Hyperoptic to be allowed to install.

I will contact BT but at the moment I am still waiting for them to contact me about the engineer no-show.

If there were large outages is it conceivable that there is reduced capacity and more than 32 people sharing the 2.5 Gbps while repairs happen?

I would say it might be an issue at your exchange going to BT's Network due to you should never drop that low going to your exchange.

TBH if it was me I would phone up BT tomorrow to report this issue ,sure they might be aware of it, but they might not, and at the same time you could "enquire" about the engineer visit.

As for more than 32 people sharing the 2.5Gbps to the exchange, that's cannot be the case, the Splitter node splits up 1 fibre into 32 smaller fibres and a Splitter Node can take in 4 fibre to create 128 fibre connections.

Paul

In reply to a post by Brookzy:

Well here is something... I put my number into the service status checker to see if there were any reported issues and it appears there is an open fault report in relation to the connection which was opened on Friday - the day the engineer was meant to show up but no-showed. I haven't contacted them about this at all nor have I received any contact about that fault. And it doesn't show up on the My BT page.

Maybe they're onto it already!

Screenshot: https://cl.ly/37293Y0X030b

Ah, that makes sense and why your speed was dropping that low.

TBH I thought it might of been the hardware that provides fibre to your area that was at fault, something like where it chops up the block of 32 connections into segments, if that went doolaly it might of caused issues on your connections.

But it seems going by that image that its the connection between your exchange and BT's Network.

Yeah, maybe the enginner went to the exchange and saw the issue and reported it, or maybe the system detected an issue and create a fault report, I don't think that will be linked to your account or maybe it gets added once its fixed, not too sure.

Also you "might" want to remove the fault and ONT numbers from that image.

Paul

Leaving the numbers in was a calculated risk knowing that some guys around here have access to certain systems and might shed more light on the fault... Have removed it now.

Sure enough, now it's 2AM, I'm back to over 200 Mbps. It's got to be congestion.

Even if there were 128 people sharing the 2.4Gb it really wouldn't be a problem. The issue is going to be with the BT Wholesale network out from the exchange or the connection between Openreach and BT Wholesale.

I wouldn't be to surprised if it were the latter.

Brookzy

It sounds like it is not the GPON with the congestion but the Virtual path you are on from the exchange to the Core ( VLAN) these can be various different sizes used to be from 100mb ( for ADSL2+) to 850Mb ( max within 1 Gb physical) but are now likely to go bigger to fit 10GB physicals.

When they set up all the unused connections these are likely to be allocated to a small VLAN, as they won't be carrying anything other than test packets. When a customer order is completed they would be moved to that ISPs VLAN which will be at the size they pay for. ( Or a cable link to their network). This may be only 500Mb and will only be upgraded when it reaches a set % of capacity ( say 85% for 2 hours over 5 days) If several Infinity 4 customers are provided and all start to stream at 330Mb this will be congested until it is regraded ( Usually a software task) or the customers are moved to a different VLAN, as Paul was.

If your connection has only just gone live you may be on a 'small' VLAN, if it hasn't been completed in BT's systems you may still be on the original VLAN that may only be 300Mb.

Hope this explains your present situation. You may have to wait until the job is completed ( by the missing engineer!) or a couple of days before the systems automatically increase the VLAN size.

Only if the VLAN ( or VLANs) are at the physical pipe size will any human have to interfere to physically increase the pipe size, 1Gb to 2*1Gb or up to 10Gb this will take longer.

From your initial SpeedOf.me plots, there are two major takeaways:

1) Saw-toothing. This is the main 'fault'.

2) The 'trend' curve, whereby it accelerates from 0 to 213mbps before levelling off at around 160mbps.

The good news is I don't think it has anything to do with the physical connection, ie the fibre itself. The reason is you simply wouldn't even get anything close to the speeds you're getting, and the cutouts wouldn't be a recognisable pattern like the sawtooth it is and much more random.

Given the trend line is recognisable as well, this shows to me that's the GPON itself balancing load (this looks very normal if left to normal hardware to level load). If you run a SpeedOf.me in the dead of night, this curve should be higher. It could also be another (much more light-touch) traffic shaper and indeed is quite typical of a Fair Queue (FQ) plot, and indeed if two shapers were working on the same bandwidth you'd get weirdness like this as well, but again, I doubt it's shaper-related.

The bad news is there's clearly something misconfigured. While it could be shaping, I actually think this is an I/O issue, like a network driver or a diagnostic profiler such as rudimentary packet dumper that blocks network traffic while writing the dump to disk. This is what I believe is the most likely explanation, as every engineer has forgotten something like switching off a profiler before, and given this is BT we're talking about, the numbskullery is much higher than average.

Whatever it is, I agree with the others and it's pretty clear to me that this is an issue with the backhaul (between the Exchange and the Core) not in the last mile.

Thank you for all the replies. Now it's pretty much the dead of night I've run a few more speedof.me tests, results attached here: https://cl.ly/3a1T281w4643 https://cl.ly/1p0b1O442F0y https://cl.ly/0l342v0c0N0c

This evening the speeds dropped to as low as 15 Mbps so it seems to be getting worse.

Hopefully someone from Openreach will pick up the fault tomorrow!

In reply to a post by Brookzy:

Thank you for all the replies. Now it's pretty much the dead of night I've run a few more speedof.me tests, results attached here: https://cl.ly/3a1T281w4643 https://cl.ly/1p0b1O442F0y https://cl.ly/0l342v0c0N0c

This evening the speeds dropped to as low as 15 Mbps so it seems to be getting worse.

Hopefully someone from Openreach will pick up the fault tomorrow!

Just did a test on my BT connection and got >> this << yours should be near my speed.

Have you tried the speedtest on here?
https://www.thinkbroadband.com/speedtest

Paul

Yeah I wish I was getting that!

The speedtest does not look typically indicative of congestion, but more end-user setup e.g. WiFi and/or the device in use.

Congestion usually displays a huge gap between the AVG TBB Download and AVG HTTPx6 Download. You do have a gap, but not as large as I would expect with congestion.

Have you raised the issue with BT Consumer? The good news is congestion to this scale (if indeed congestion) is rare, and where it does exist they usually resolve it. On the FTTP lines we do see more speed slowdowns, just due to the headline speeds being that much higher, not to your extent though typically.

https://speedof.me/show.php?img=180514021240-7545.png

https://speedof.me/show.php?img=180514021858-5699.png



Well that's an improvement! Let's hope it stays that way.

ukhardy07 - there's a fault already logged with BT, I am waiting for them to contact me about an engineer no-show on Friday.

In reply to a post by zzing123:

From your initial SpeedOf.me plots, there are two major takeaways:

1) Saw-toothing. This is the main 'fault'.

I don't understand why the saw-toothing is an issue when the speed test is downloading different sized files consecutively. It's what I would be expecting. Also being singe-threaded the results can be lower that other speed tests.

Brookzy

That looks like a VLAN size change and is around the right time span too. The system is only likely to resize in steps so you may find in increases again in a week or so time.

The difference between the single and Multi thread at that time of night may also indicate a limit within your computer. It may be that each core is only capable of a speed lower than your service max, this is fairly common when you get a high speed service but doesn't bother most people as they want the speed for multiple devices rather than pure speed to one device.

People with 1Gb services need high spec devices to reach anywhere near the full speed on one device as Disk write and CPU issue start to effect tests.