Low single thread speed

[Gary]

I was wondering if anyone else is seeing this if they are on a Zen pop, though Idnet. Support have said they could move me, that was before Christmas but normally my line works well. I wanted to know if anyone else has this issue, as it might be something more local rather than a zen/idnet backhaul issue.

[Bill]

That's very similar to mine... it's a Zen problem.

IDNet are trying to find out what the problem is, and if it can be fixed. If Zen can't (or won't) fix it then, like you, I've been offered a backhaul switch.

[Gary]

Cheers, Bill. I think Jonathan Green is the guy they need to talk to he is the core network engineer at Zen, and was who Brian talked to last time when this happened I'm pretty sure. Ive seen people having issues with TTB backhaul too as I read Zenuse talk talk LLU equipment to connect to Zens own pops from local exchanges if they are satellites like mine is.

[nowster]

And I thought all the guys at Zen were called Dave...

(Currently sitting about a quarter of a mile from Sandbrook Park.)

[Bill]

I supplied Simon with some test data I'd garnered and it's magically gone back to where it should be:



Some signs of slight congestion developing later on as t'internet wakes up, but we'll see how it goes during the day.

How about yours Gary?

[Gary]

I supplied Simon with some test data I'd garnered and it's magically gone back to where it should be:



Some signs of slight congestion developing later on as t'internet wakes up, but we'll see how it goes during the day.

How about yours Gary?

Same here Bill. Just checked mine and its back how it should be pretty much, congestion on my upstream, I use Qualcomm's  streamboost QoS so I'll re-set my throughput settings later and see how it goes. 

[jaydub]

That's very similar to mine... it's a Zen problem.

IDNet are trying to find out what the problem is, and if it can be fixed. If Zen can't (or won't) fix it then, like you, I've been offered a backhaul switch.

Where was Brian planning on switching you to?  TTB or BTW?

I am on a TTB backhaul at the moment and have very inconsistent single thread speeds.  I am being shifted to a BTW backhaul on Monday to try and rule out LLU equipment at the fibre exchange .

jdigz7 on TTB was suffering from evening congestion on BTW and is seeing similarly intermittent single thread speeds, just like me.

On the other hand, Roksan (who I think is Musical4Ever here) was moved from BTW to TTB and is now seeing perfect single thread speeds as far as I know.

Just goes to show it's all a bit less than straightforward.

Glad you guys appear to be sorted.  I'm keeping my fingers crossed for Monday!

[Bill]

Where was Brian planning on switching you to?  TTB or BTW?

No idea, the matter hasn't come up yet

Seems OK at the moment, possibly some moderate evening congestion but I need to collect more data. It only really affects 4K streaming (specifically, how fast iPlayer etc thinks my line is) and there's not a lot of that about yet, so no great rush.

I'd rather stay with Zen if possible, gut feeling is that any problems are more likely to get sorted with them than with TTB or BTW, but we'll see how it goes.

Just goes to show it's all a bit less than straightforward.

Tell me about it 

[jaydub]

No idea, the matter hasn't come up yet

Seems OK at the moment, possibly some moderate evening congestion but I need to collect more data. It only really affects 4K streaming (specifically, how fast iPlayer etc thinks my line is) and there's not a lot of that about yet, so no great rush.

I'd rather stay with Zen if possible, gut feeling is that any problems are more likely to get sorted with them than with TTB or BTW, but we'll see how it goes.

Tell me about it 

Thanks for the update.  I can relate to your desire to stay with Zen, as I suspect you are right.

If Brian had given me a choice, I think I would have opted for Zen over BTW.

I have a spreadsheet of all my TTB results for the last 3 months, which makes interesting reading.  They are much more akin to my results from when I was with Pulse8 on a resold TTB product than when I was with Aquiss (on a BTW backhaul), where the only problems I generally had were during the day when their business prioritisation had a significant impact on the ping response times as seen on my BQM monitor and on the single thread speeds.

It is the off-peak Aquiss results that give me some real hope of an improvement come Monday.  Time will tell!!

[Gary]

4K streaming and 4K HDR are all working fine now and I've gained a whole 1Mbs after ast night at 11pm. I'm not complaining though.  I've not noticed any evening congestion but that could easily be localised I suppose. 

[Gary]

Where was Brian planning on switching you to?  TTB or BTW?

I'm not sure about Bill, but they were thinking of transferring me to TTB Backhaul. Glad that didn't have to happen, although I still lament having a tiny battery fault a year or so back and being put on an awful pair loosing myself 7Mbps which I'll never get back. I used to get  62-64Mbps now its 54-55Mbps. Battery faults don't really effect Broadband, HR faults do though. That was a Zen issue with single thread again and of course loosing the 7Mbps never cured that issue, but Brian did when communicating with Zen. It seems to be  a recurring theme.

[Bill]

I have a spreadsheet of all my TTB results for the last 3 months, which makes interesting reading.

Ditto 

Noticed something interesting tonight- my "idle" BQM ping is ~10mSec, watching some UHD on Amazon (which was only streaming at ~15Mbps) it went up to ~25mSec, but tried a bit of Blue Planet 2 (which streams at ~23Mbps)  and it only went up to ~12-13mSec. Seems the Beeb knows what it's doing

No buffering, although speed test still suggesting some congestion in the evenings:

[Gary]

Ditto 

Noticed something interesting tonight- my "idle" BQM ping is ~10mSec, watching some UHD on Amazon (which was only streaming at ~15Mbps) it went up to ~25mSec, but tried a bit of Blue Planet 2 (which streams at ~23Mbps)  and it only went up to ~12-13mSec. Seems the Beeb knows what it's doing

No buffering, although speed test still suggesting some congestion in the evenings:

I did a check Saturday and Sunday night, I noticed some evening congestion has crept back in, but all streaming is working well, Netflix and Amazon, YouTube and BBC iPlayer all stream without issue with 4K and 4K HDR.

Depending on load with other stuff in the house a router with a good QoS can help to prioritise device and applications. I found for myself the Qualcomm streamboost system which is set and forget pretty much as it has a cloud database of devices and apps, it updates now and then and seems to work well. For instance making sure iPlayer gets what it needs vs say a tablet browsing or a Bluetooth speaker playing, so priority for bandwidth and latency are kept in check for each device and what's used on it.

I do wonder though how reliable speed checks are, TBB I think runs off Zens servers but I may be wrong, but DSL Reports always gives my bufferbloat a score of A+ a lot depends on servers being used for these tests I guess, as congestion can happen anywhere along the path. If you say use the Ookla multithread speed test you can get a large variation just using servers in London for instance. I did Notice that Zen have quite a few area codes being worked on in the next day or so including mine, so I'll keep watching.

[jaydub]

I do wonder though how reliable speed checks are, TBB I think runs off Zens servers but I may be wrong, but DSL Reports always gives my bufferbloat a score of A+ a lot depends on servers being used for these tests I guess, as congestion can happen anywhere along the path. If you say use the Ookla multithread speed test you can get a large variation just using servers in London for instance. I did Notice that Zen have quite a few area codes being worked on in the next day or so including mine, so I'll keep watching.

I'm pretty certain that TBB's testers are hosted in their data centre in London and Zen just make use of them.

In terms of reliability on the TBB tester, what do you see if you do three tests one after another?  Consistent results or significant variation between them.

I know I'm on a TTB backhaul (until some time later today) so definitely not directly comparable, but my last three results at just after midnight this morning were: 52.4, 61.5 & 68.1Mbps.  This variation is typical of what I see whatever time of day I test.

[Bill]

I thought (briefly) about applying QoS, but I live alone so if anything starts competing for bandwidth it must have been me who started it, so it's up to me to stop it 

Speed tests- afaik tbb use exclusively their own servers. Partly so that, if something goes wrong, they know they can fix it and partly because of Seb's (self-confessed) paranoia about security. If he could find a way to block all external connections whilst maintaining internet access, he would . And as for Ookla-based tests... they're good for bragging rights but useless for anything diagnostic, they discard nearly half the data- Ookla methodology.

The congestion I'm getting is more than it really should be, but not enough to cause problems. I suppose I could ask for a backhaul change, but considering the alternatives I'd rather stick with the devil I know   (For the moment anyway.)

On a more general note, I think the increasing affordability of 4K smart TVs is going to give some ISPs (no names...) real problems with the amount of bandwidth/customer they provision...

I did Notice that Zen have quite a few area codes being worked on

Have you got the link for that, sounds useful?

[Gary]

I thought (briefly) about applying QoS, but I live alone so if anything starts competing for bandwidth it must have been me who started it, so it's up to me to stop it 

Speed tests- afaik tbb use exclusively their own servers. Partly so that, if something goes wrong, they know they can fix it and partly because of Seb's (self-confessed) paranoia about security. If he could find a way to block all external connections whilst maintaining internet access, he would . And as for Ookla-based tests... they're good for bragging rights but useless for anything diagnostic, they discard nearly half the data- Ookla methodology.

The congestion I'm getting is more than it really should be, but not enough to cause problems. I suppose I could ask for a backhaul change, but considering the alternatives I'd rather stick with the devil I know   (For the moment anyway.)

On a more general note, I think the increasing affordability of 4K smart TVs is going to give some ISPs (no names...) real problems with the amount of bandwidth/customer they provision...

Have you got the link for that, sounds useful?

Here is the link, Bill. https://status.zen.co.uk/broadband/ Just type your area code in and see what comes up.

[Bill]

Here is the link, Bill. https://status.zen.co.uk/broadband/ Just type your area code in and see what comes up.

Thanks- nothing on my area code, but there's nothing serious wrong so I wasn't really expecting anything!

[Gary]

Thanks- nothing on my area code, but there's nothing serious wrong so I wasn't really expecting anything!

Mine list loads of area codes plus mine for the 16th and 17th, maybe things are falling apart here  I agree with the 4K TV demand issue, 4K TV's are now cheap and many now have HDR10 and Dolby Vision and HLG HDR too, so even more bandwidth needed. Sadly I have noticed the shops selling those TV's don't make it clear that to steam at these resolutions you need a minimum bandwidth which is a bit sneaky. I can see in the evening congestion will probably get worse over time before it gets better for many ISP's. Also 4K gaming and te huge patches needed will tax the system even more. Let alone 4K screens on Phones. (my eyes could not tell the difference on screens that small)

[jaydub]

There is a Zen customer on TBB that has just raised the subject of poor single thread speeds:

http://forums.thinkbroadband.com/zen/t/4580234-return-of-the-dreaded-slow-single-thread-download-test.html

You are not alone.

[Bill]

I see he's up in the wilds of Scotland... the Zen engineers must feel as though they're playing Whack-a-mole 

[nowster]

I see he's up in the wilds of Scotland... the Zen engineers must feel as though they're playing Whack-a-mole 

Actually, with the coming of 4G mobile to Aberdaron (remote NW Wales) this week, it's actually starting to look viable to drop the ADSL Max (2Mbps on a good day) for a data-only mobile package. Currently it's £22/month for 15GB at 4G speed vs. £20/month for 50GB of slow ADSL Max.

[Bill]

Currently it's £22/month for 15GB at 4G speed

It's probably a good thing that 4G can't handle UHD speeds... 15GB is about one and a half episodes of Blue Planet 2 

[nowster]

Actually 4G can do up to 60Mbps with some mobile companies. The theoretical max is about 150Mbps, IIRC.

[Gary]

Actually 4G can do up to 60Mbps with some mobile companies. The theoretical max is about 150Mbps, IIRC.

I get over 100Mbps where I live with EE but still data wise wwatching UHD/UHD HDR content via 4G would eat data like crazy.

[Gary]

There is a Zen customer on TBB that has just raised the subject of poor single thread speeds:

http://forums.thinkbroadband.com/zen/t/4580234-return-of-the-dreaded-slow-single-thread-download-test.html

You are not alone.

Mines pretty much back to what it was, although there is engineering work tonight to a large amount of post codes (including mine)  Then on the 18th, 19th, 22nd which all include mine again then just my postcode on the 23rd. Maybe the congestion on the upstream may get smoothed out

[Bill]

My code has appeared for some work tonight... and, depending what's involved, work on other codes could have an effect on mine anyway.

A couple of speed tests this morning lead to some (very) cautious optimism... 

[jaydub]

I too am feeling somewhat happier this morning having migrated from TTB Backhaul to BTW.  It's eraly day's yet, but my TBB speed tests have averaged 70.5Mbps this morning.  Still a bit down on the multithread average of 74.1, but much better than I was seeing on the TTB backhaul, which has averaged 59.6 since I migrated in a month ago.

There is still some interesting variations in some results, but probably not worth worrying about.

[jaydub]

Just one final question as it went unanswered before.

If you do three consecutive TBB speed tests, how consistent are the single thread speeds?

Although life is much better on a BTW backhaul, I still see a significant variation between the fastest and slowest results of the three the vast majority of the time.

[Gary]

Just one final question as it went unanswered before.

If you do three consecutive TBB speed tests, how consistent are the single thread speeds?

Although life is much better on a BTW backhaul, I still see a significant variation between the fastest and slowest results of the three the vast majority of the time.

Depending on your router, the load on the speed test server, congestion, contention, crosstalk and all the various other radio waves that cause background interference at various times of day, plus the laws of physics I think there will always be some variation. As long as single thread is pretty close to the multi thread score you are doing the best you can, considering this is a post war copper (with some aluminium) network with a bit of fibre stuck on in places that was never designed to do any of this in the first place

[Bill]

I still see a significant variation between the fastest and slowest results of the three the vast majority of the time.

Depends what you mean by "significant"... congestion being what it is, I'd expect to see variations of anything up to ~5Mbps, maybe more, between them. And on the odd occasions I run that sort of test, I often do.

I'm coming at it from a different direction- I've been running speed tests at intervals during the day and putting them into a scatter plot to get a "congestion profile" over the day... the 1x tests are virtually always a few Mbps below the 6x ones, don't mind that, but there's a marked shortage of bandwidth somewhere from about 8pm to 11pm... 1x speed falls by about half. It's not causing me any problems at the moment, but doesn't bode well for the future.

Trouble is, data collection is a very slow process 

[jaydub]

Depends what you mean by "significant"... congestion being what it is, I'd expect to see variations of anything up to ~5Mbps, maybe more, between them. And on the odd occasions I run that sort of test, I often do.

I'm coming at it from a different direction- I've been running speed tests at intervals during the day and putting them into a scatter plot to get a "congestion profile" over the day... the 1x tests are virtually always a few Mbps below the 6x ones, don't mind that, but there's a marked shortage of bandwidth somewhere from about 8pm to 11pm... 1x speed falls by about half. It's not causing me any problems at the moment, but doesn't bode well for the future.

Trouble is, data collection is a very slow process 

I too am doing a scatter plot with my speed test data.  I'm probably doing the same as you in terms of testing during the day, it's just that I do three consecutive tests at a time rather than just a single test.

I haven't seen any time of day impact with my connection on either TTB or BTW backhauls and wouldn't have thought it wouldn't be an issue for the Zen backhaul either.

Here's a plot of my IDNet connections.  Quite marked how much better the BTW backhaul has been on my connection.



The mean is over 10Mbps higher and the median about 8Mbps higher and there is significantly less scatter in the results (the SD has more than halved).

Still a few outlying results, but I guess that is to be expected.

[Bill]

You're running a lot more speed tests than I am 

Certainly it's an improvement, but tbh it's not a lot better than I'm seeing now, and I'd still call that a congested connection... but tastes vary 

I use Dropbox which doesn't allow embedded links, but I've put my results in a PDF you can see- https://www.dropbox.com/s/zr9x6pjdw69yq8x/Congestion.pdf?dl=0

(Just kill the "Sign Up" box if you get one)

It's plotted differently to yours, and the worst of the ~2pm and evening peaks seem to have gone since the work Zen did on Monday night, but too early to be sure.

I haven't seen any time of day impact with my connection on either TTB or BTW backhauls and wouldn't have thought it wouldn't be an issue for the Zen backhaul either.

Well something is... IDNet claim no contention on their network so it must be on Zen's. Either Zen are congested at my exchange or IDNet haven't bought enough backhaul bandwidth (or both!), no way of telling from here. But it's not yet bad enough to get excited about afaic.

[jaydub]

Ive split out my results to just display the results following the move to the BTW backhaul.



It looks as though I have a lot more tests that are close to the TBBx6 result, with a smallish proportion of outliers.

At the end of the day, we are not guaranteed a congestion free connection, so I am trying to apply a certain level of pragmatism that there will always be a few results that are out of kilter with the majority.

Remember congestion can be at the cabinet level as well as the exchange.  Zen are certainly able to monitor traffic levels al the way up to the GEA Link in the exchange.

Below is a paraphrase of an explanation I got from Jon Green at Zen, when I was thinking of joining them.

On Zen LLU, we get control of your connection as a PPPoE session at your parent exchange, and then route it through our backhaul network to one of our central PoPs.  Our Network Ops team monitor and manage the capacity on the various parts of our network.

Conversely, a BTWholesale connection would be backhauled from the exchange through BT's network, and then we'd get the connection in one of our central PoPs, so we'd have no direct control of the bit between your exchange and our network.

I assume the latter statement is equally true for IDNet.

I would certainly like to see better, but I don't think I have enough of an issue to push Brian for a further change, particularly since the only other backhaul option is Zen and I'm not sure moving to Zen at the moment would actually improve things.

[Bill]

At the end of the day, we are not guaranteed a congestion free connection, so I am trying to apply a certain level of pragmatism that there will always be a few results that are out of kilter with the majority.

I agree completely, but pragmatism can change with circumstances, and if I hadn't bought a 4K smart TV just before Christmas it's unlikely that I'd taking much notice at all of single-thread speeds, and certainly not plotting them! Multiple thread speed seldom drops more than a meg or so from it's usual 67, and on a decent-sized download it'll normally max out the line.

Even for UHD/HDR streaming it works fine most of the time, but there's not much room for it to get any worse...especially during the evening.

Remember congestion can be at the cabinet level as well as the exchange.

That's why I've been on Zen backhaul for the last few years 

I had a problem that was eventually traced to congestion on my cabinet, BT showed no inclination to fix it so Simon swapped me to a Zen SVLAN. But the problem showed as severe packet loss, which isn't the case this time. Probably doesn't prove it's not the cabinet again, but it's all I've got to go on.

[Bill]

the worst of the ~2pm and evening peaks seem to have gone

Oh no they haven't... 

[andrue]

I'm pretty certain that TBB's testers are hosted in their data centre in London and Zen just make use of them.et

Yes. TBB is owned/operated by NetConnex.

About Us.

"Our staff work for thinkbroadband along side full time jobs at hosting company NetConnex (ncuk.com) providing business cloud servers, co-location and VPS/dedicated servers within the Telehouse Docklands datacentre, including hosting the thinkbroadband infrastructure and speed test platform. "

[andrue]

I had a couple of poor single thread results tonight (I'm on BTW backhaul) but it seems to have recovered now. It's noticeable on my TBBQM though that there's increased latency during peak hours last couple of days. I'm keeping an eye on it.

[Bill]

It's noticeable on my TBBQM though that there's increased latency during peak hours last couple of days.

That's something I'm seeing no sign of whatever...

[Adrian]

I am seeing that too.

[jaydub]

I had a couple of poor single thread results tonight (I'm on BTW backhaul) but it seems to have recovered now. It's noticeable on my TBBQM though that there's increased latency during peak hours last couple of days. I'm keeping an eye on it.

I am also on BTW and had a set of poorer than normal results this afternoon.  I've been out this evening, so not sure whether it has improved or not.

I had a bad day for latency on my migration day to BTW (Tuesday) with the BQM graph showing the maximum ping (yellow responses) to be bad from 2pm to about 8:30pm, but it's been OK since.

[Gary]

Since the vast amount of Zen work being done things are much better, still have more next week including one that is just for my postcode, but I am pretty content with how things are at this time.

[jaydub]

Looking good, Gary.

My connection was very poor yesterday afternoon with one single thread result as low as 13.6Mbps, before jumping back up to normal speeds.

I suspect congestion on BTW equipment at the exchange or on the backhaul, but need to collect more stats to prove the point.

[Bill]

No change here, but my area code is on the list for more work towards the end of next week, so there's hope yet