Affect on speeds of the Plusnet profile

[#1]

The BT IP / PN IP both on 77Mb are all ok but it just throughput speed of 72Mb is bit lower (5Mb less than the IP Profile) as I am expected to see around 75Mb throughput speed.

[#2]

I don't think it's that the plusnet current line speed limit is lower than what it shows as such. It's that things are quite capable of going faster if the plusnet profile weren't in the way.
AndyH - just ask for your PN profile to be temporarily set to 110Mb and see how fast you can download (ideally a 5 minute or so sustained download, so people won't try to explain the difference away by network buffering and speedtester inaccuracies etc.).

[#3]

Quote from: ejs

I don't think it's that the plusnet current line speed limit is lower than what it shows as such. It's that things are quite capable of going faster if the plusnet profile weren't in the way. AndyH - just ask for your PN profile to be temporarily set to 110Mb and see how fast you can download (ideally a 5 minute or so sustained download, so people won't try to explain the difference away by network buffering and speedtester inaccuracies etc.).

I did ask Plusnet to try put my profile at 82Mb for one hour to try it and see how fast my throughput is from BT IP at 77Mb. But, they rejected and refused it.

[#4]

I just spoken to the tech support at Plusnet and they push my PN IP Profile at 78Mb and I am now getting 2Meg extra of throughput speed on 74Meg instead of 72Meg on BTw speed throughput. Proof here below :

I hope my PN IP Profile staying at 78Mb. Strange BTw IP profile also increase from 77.42Mb to 77.44Mb now after Plusnet adjusted PN IP from 77.4Mb to 78Mb. That's rather weirdo. But BT IP does matched my sync rate correct at 79999K now.

[#5]

What if my Plusnet profile is set to a lower speed like 77.42? If goldenfibre is right, then I should get the same speeds as him.
Could it also be anything to do with this:

@ goldenfibre - It's a good thing you're not on FTTP 330/20...there's a lot of variance in the speed results on this with my neighbour

[#6]

If Plusnet revert me back to 77.4Mb again then I will complaint because it will lose 2Meg off it. It's should stay and fixed at 78Mb. I just knew it from my own experience. AndyH - you can phone up and ask plusnet to set your profile at the maximum rate. I been told by BT, Zen, ICUK and IDNet tech support last week that they do not limit their own ip profile capped at their side for fibre. They leave it by BTw profile capped itself. Why should Plusnet do the same.

[#7]

I don't think a PN profile of 78 is high enough to demonstrate what the full speed of 80Mb FTTC would be without the PN profile restricting it.

Quote from: goldenfibre

I been told by BT, Zen, ICUK and IDNet tech support last week that they do not limit their own ip profile capped at their side for fibre.

That's strange because according to BT SIN 498 it says:

Quote

2.1.6 Downstream shaping The CP is expected to shape the downstream traffic to match the actual VDSL2 line rate in order to avoid excessive traffic loss.

[#8]

Slightly confused by what you're saying.
It was always my understanding that all ISPs have to implement their own speed profiles for lines otherwise data can be sent down too quickly, which will cause packets to buffer or be lost:
I really do not think Plusnet are trying to short change you out of a few Mb here....
***Edit - deleted - duplication with ejs

[#9]

Quote from: ejs

That's strange because according to BT SIN 498 it says: Quote 2.1.6 Downstream shaping The CP is expected to shape the downstream traffic to match the actual VDSL2 line rate in order to avoid excessive traffic loss.

Then the ISP's probably ignore it more likely

[#10]

Kelly gave an explanation of things a while back:

Quote from: Kelly

There are 5 potential speed points on your line, applied in this order: 1 - Your theoretical speed.  This is the quality of your line.  You will never get higher than this without technology changes 2 - Your BT Speed Profile.  This is a profile set on your line which the exchange equipment has determined as your stable speed.  On a good, stable line this will set and shouldn't change too much.  If you have an unstable line, it will theoretically decrease until your line becomes stable. 3 - Your Plusnet speed profile.  This is set to a little below your BT speed profile.  We do this so that we can control the maximum amount of data we send down your line. This allow us to use our QoS to protect your experience.     5 - Rate limits.  We are able to apply a rate limit across our traffic.   We do this on our Essential, Plus, Extra and legacy accounts at peak hours for protocols like P2P.  Our current Unlimited product does not have any. 6 - QoS level buffering/packet drops.  Because we've identified the types of traffic you are using, we can cause packets of those particular types to buffer, and eventually drop.  We use this to ensure that, along with your Plusnet speed profile, if you are maxing your bandwidth, we'll make sure you get your high priority packets first.  If our network is also under heavy load (i.e. we've cocked up our bandwidth forecasting) this will start to apply to ensure time sensitive traffic is protected at the expense of the less time sensitive traffic. Unlimited has no 5, and 6 is applied on a per user level if you are maxing your line.   6 is always in affect, but our WBMC network is scaled so that no buffering is happening.  (There has been a little bit on IPSC over the past few weeks which I'm working with Dave T to fix) We can set 3 at any time by hand, but is usually automatically adjusted a couple of times a day based on messages from BT about what 2 is set as.  (THere are some issues in the messages coming from BT on this.)  This manual adjustment is what I did for Finguz We can't influence 1 at all, beyond advising you to fix dodgy cables and sending engineers.

AAISP match the IP Profile their end - http://aa.net.uk/kb-broadband-shaping.html
I think it's best practice to have the IP Profile match at the ISP end because it stops them trying to send data to your connection at a faster rate than it can handle/the BTw IP Profile has been set to.

[#11]

My BT profile was never anywhere near 7.15, never has been nor ever will be. While my BT profile was 3.1, but due to my Plusnet "it's incredibly difficult to pass a number from one system to another" profile somehow ending up being set to 7.15, I could sustain download speeds of 380kB/s. After the only thing changing being the Plusnet profile changing to match the BT profile of 3.1, my max download speed was then 356kB/s.
The Plusnet current line speed is underestimating how fast data can actually be transferred down the line. OK sure, it's just being set to the same number as the BT IP Profile (when the updating system works, that is). Perhaps the BT IP Profile is similarly underestimating how much data can be transferred down the line, or perhaps something at Plusnet is not correctly allowing for all the various layers of protocols and packet headers.

Quote from: AndyH

Kelly gave an explanation of things a while back: Quote from: Kelly 2 - Your BT Speed Profile.  This is a profile set on your line which the exchange equipment has determined as your stable speed.  On a good, stable line this will set and shouldn't change too much.  If you have an unstable line, it will theoretically decrease until your line becomes stable.

That explanation of the BT profile sounds misleading to me, which makes me angry. The BT profile is determined by your line sync speed, and there's nothing more to it than that. If you have an unstable line, your line sync speed will end up being decreased. On a good line, the BT profile is still set based on your line sync speed.
Also, the 5 points are obviously applied in reverse order as data travels from Plusnet towards the end user, starting at 6 / 5, (no point 4?), then 3, then maybe 2, and finally 1.
As I quoted earlier, it even states in the IPstream max handbook, on page 37, that the maximum speed you can see is limited by your line speed and not by the BT IP profile, but that PDF was only applicable to 20CN ADSL max, and there isn't any similar publicly available documentation for 21CN.

[#12]

Yeah I just hate stupid profile things. Virgin Media Cable (Fibre) isn't on any profiling capped. Virgin Media say 50Meg you will get 55, 100Meg you will get 104 and 152Meg you will get 160. BT always lower than sync rate then lower again after ip profile on Fibre. You don't need profile on the fibre!

[#13]

Quote from: goldenfibre

You don't need profile on the fibre!

Is this right though?
For example, If you are synced at 45Mb/s but provisioned on 80/20Mb/s - how would Plusnet's systems know what speed to send data down your line? If they send the data down at 80Mb/s, your line would be unable to handle this speed and packets would buffer/time out and request to be resent.
I am also struggling to understand how effective the Plusnet Line Speed profile actually is, because I can download at higher speeds than the profile (there is a mismatch between what my IP Profile/Line Speed are set at, but I don't really care for an extra 2Mb or so) . As ejs says, this is suppose to be impossible - but I have even had speed test results higher than my IP Profile before. Perhaps this is a false positive from the flash speed test sites (which may not be 100% accurate)?
I understand that your actual speed will always be lower than your sync speed due to TCP overheads etc.
Edit: I should add that I don't think Plusnet are doing anything wrong here - they are just implementing something which is regarded as best practice for an ISP.

[#14]

Quote from: goldenfibre

I been told by BT, Zen, ICUK and IDNet tech support last week that they do not limit their own ip profile capped at their side for fibre. They leave it by BTw profile capped itself. Why should Plusnet do the same.

~Wild speculation~
Cost savings  & how the arbors  need to work.

[#15]

Does it save costs though?
All ISPs that use the 21CN network pay BT Wholesale £40 per month per 1Mb/s of bandwidth. Plusnet is paying millions each months to BT Wholesale for this bandwidth (http://www.plus.net/support/service/network_performance/broadband_bandwidth_usage.shtml).
Edit: I roughly worked out they were paying £4-5 million a month in bandwidth charges...
If there are no controls implemented on the speed at which they send data to their end users, then surely it's the same as throwing money down the drain?