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Just how are profiles applied?

jack21
Grafter
Posts: 180
Registered: 25-02-2009

Just how are profiles applied?

I'm puzzled as to exactly how the I/P profiles are applied...which one of the 2 I/P profiles is applied to the line - the BT one or the Plusnet one (or both!).  Can anyone enlighten me please.
Several times recently, my BT and Plusnet I/P profiles haven't matched; at the moment my BT profile is 1000 (2 days ago my sync rate dropped from above 1440 to around 1052 for 5 mins when I tried another router), my Plusnet profile is 750 (though it too was 1000 yesterday) and my sync rate has been over 1700 for 48 hours......but several speedtesters give me around 690kbps, which indicates the Plusnet profile applies. On another occasion, the Plusnet profile was higher, the BT profile was lower, and speedtests matched the lower profile, suggesting the BT profile applied. Is it the case that the lowest of the 2 profile always applies?
Is the Plusnet profile 'copied'  from the BT profile at fixed times (what are they?) once or twice a day, or is some other method used.
Thanks.
26 REPLIES
Laser
Grafter
Posts: 206
Registered: 23-09-2007

Re: Just how are profiles applied?

The BT BRAS profile is set by BT and is always a little lower than your lowest recent sync rate. It's a highly contentious issue because there is no justifiable reason for it, and the way it is managed is stacked very much against the customer. However, I'm afraid you just have to take it as a given if you use a BT-based ADSL connection.
The number that appears on the PN portal is what PN last got told it was set to. PN don't actually apply anything, the number is just there for your information. It is usually a few hours out of date because it is second-hand information.
PN do, however, further restrict your connection according to the traffic management profiles for your package type. There may also be a general slow-down when the network is busy, but they try to minimise that.
So, at any given time, you should get speeds in the region of whichever is the lowest number out of the traffic management rate for that time of day and the BT BRAS profile applied to your line.
jack21
Grafter
Posts: 180
Registered: 25-02-2009

Re: Just how are profiles applied?

Thanks Laser, thats good knowing that just the BT profile applies....that the Plusnet profile may be some time out of date.
I'm on BBYW1, so the stuff I do is by and large unrestricted/linespeed (email, browsing, speedtests), and possibly-shaped infrequent small downloads and updates, so I'm surprised that a BT speedtest says 1000 profile, but only says 690 downspeed......I expect it'll stabilise eventually tho, and as my router has been around 2100 for the last 2 days, I expect a profile rise to 1750 in due course.
It is possible that I'm not helping as I've started switching my new router off overnight (its hardwired SNRM of 6 is too low for my 68db line at night - frequent drops) and use it only from 7:00 to 17:00 when it performs brilliantly at SNRM 7.5<>5.5, but since beginning to use it 50 hours ago, haven't seen a sync rate less than 2000.
Community Veteran
Posts: 19,101
Thanks: 443
Fixes: 21
Registered: 31-08-2007

Re: Just how are profiles applied?

Hi jack21,
Both apply. I'm afraid what Laser has said is wrong. It is the lowest of the profiles that will apply. The BT profile does determine what the PN one is, the PN one is usually updated from the BT  one twice a day, so as you have observed the change to the PN can be behind the BT one.
The sync speed is what determines the profile (as Laser said but for the wrong reasons). The profile is always lower than the sync speed, this is to prevent bottlenecks at the exchange & elsewhere hence no data loss when packets are transmitted, and further more the actual data throughput speed cannot exceed the profile and the profile is less than the sync speed because of TCP/IP overheads and the like.
If you have a low sync event your profile will drop as a consequence. If and when your sync speed recovers, then your profile will go back up, but this can take 3-5days depending on the speeds involved . This is the contenious bit, compounded by the fact that profiles sometimes stick.
If your data throughput is significantly less than your profile, this can be due to problems with your setup, congestion at the exchange (not PN's fault) or problems, traffic management at the ISP. I hope that clarifies things.
Laser
Grafter
Posts: 206
Registered: 23-09-2007

Re: Just how are profiles applied?

Quote from: Anotherone
I'm afraid what Laser has said is wrong. It is the lowest of the profiles that will apply...
The sync speed is what determines the profile (as Laser said but for the wrong reasons).

Oh dear, I seem to have upset somebody! Lips are sealed
But really, I have to defend what I said here. As far as I have ever read, there is a BT-applied speed profile (the BRAS) which is derived from your sync speed. The portal page "high speed broadband" reports this figure, but may be slightly out of date.
The only additional throttling that PN apply is for traffic management, or just inherently in the fact that there may be limited bandwidth when the network is busy. And I did say that the lowest of these two will apply. AFAIK there is no "line speed" throttle applied by PN.
I'd be happy if a PN rep wants to correct that.
jack21
Grafter
Posts: 180
Registered: 25-02-2009

Re: Just how are profiles applied?

Hi Anotherone,
What you say does appear to be borne out by what I've experienced...on several occasions, when the profiles have been mismatched, the lowest seemed to be applied. And I have waited for a day or so, each time, to see if the profiles 'caught up' with each other - and then raised a Support Ticket to get unstuck.
I was puzzled because I too, like Laser,  had read/understood that the BT one was the applicable one, but events didn't bear that out!
It really would be good if Plusnet staff could confirm this question.
On my package, I  rarely see a sustained thruput/speedtest which is less than about 95% of the profile rate, so I don't think I'm being traffic-shaped or suffering from contention......just this profile mismatching - three episodes in the last 2 weeks.
Thanks
Jack
Community Veteran
Posts: 19,101
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Registered: 31-08-2007

Re: Just how are profiles applied?

No Laser, you haven't upset me at all, you just unintentionally I expect, gave jack21 the wrong impression about how it worked and why.
Quote
But really, I have to defend what I said here. As far as I have ever read, there is a BT-applied speed profile (the BRAS) which is derived from your sync speed. The portal page "high speed broadband" reports this figure, but may be slightly out of date.
True - but it also controls your throughput. eg. if the BT one was 5000, and then PN was still at 1000, your throughput would not exceed 1000.
You previously said
Quote
The BT BRAS profile is set by BT and is always a little lower than your lowest recent sync rate. It's a highly contentious issue because there is no justifiable reason for it,
There is a justifiable reason as I explained. The contentious bit is the time the BT profile takes to recover.
You actually said
Quote
The number that appears on the PN portal is what PN last got told it was set to. PN don't actually apply anything, the number is just there for your information. It is usually a few hours out of date because it is second-hand information.
As I've re-iterated, it does control your throughput.
Quote
The only additional throttling that PN apply is for traffic management, or just inherently in the fact that there may be limited bandwidth when the network is busy. And I did say that the lowest of these two will apply. ..........
The first bit is correct, we've just cleared up the last bit
Quote
...........AFAIK there is no "line speed" throttle applied by PN.
If you are referring to sync speed there, then that is correct. The various different terms used by different organisations is very confusing, not helped by OFCOM's recent meddling. The "Line Speed" referred at the portal is the "Data Rate" as inferred by the page link https://portal.plus.net/my.html?action=data_transfer_speed and as explained it does control throughput, this is really so that there is not data loss & contention on the Network - not in any users interest.
Hi again jack21,
If you've had a number of bRAS profile changes lately, there may be something undesirable happening, can you explain a bit more about it and perhaps post the latest modem/router ADSL stats. If I remember correctly, you are on a long line.
jack21
Grafter
Posts: 180
Registered: 25-02-2009

Re: Just how are profiles applied?

Hi Anotherone,
Yes, your memory is spot on - I'm on a long 4+mile line with 68.4db attenuation. Since Mar 2009, I've bought/tried many, many modem/routers, and eventually settled on a DG834GT with DGTeam firmware. After I'd sorted out my house wiring, cut the bellwire, got ADSLnation filters, installed the DG834GT, Plusnet very kindly dropped my SNRM target from 15 to 12, then again to 9, which held for 4 months.
At SNRM 9, other routers proved as good as the DG834GT, the 2700HGV particularly (snrm-for-snrm it syncs faster than the GT), but I stayed long-term on the DG834GT and very cautiously lowered the SNRM to find my optimum linespeed with low error rates which would hold thru day&night. This obviously varied day by day, but I eventually settled for a sync rate of just over 1440 and an average SNRM of 7, and a profile of 1250. But I noticed the occasional week or two when my SNRM would rise by 2.5 or so.....during these periods, I could resync at 1900 or so....but eventually they sunk by 2.5 once more. By luck, I recently  linked these rises/drops to my neighbour going on holiday....after testing, I found he'd got an iffy 4-way power extension - when I replaced it with a new one, my SNRM rose by 2.5 and has remained so. Unfortunately, this state caused me to re-try some of my previous routers, some of which would sync at high rates, but drop connection at night - and I woke one morning to find my target SNRM at 12, and soon after at 15.
I reverted to the DG834GT, and tweaking the SNRM to 9 got me sync rates of 1600'ish and a profile of 1250 again - no problem. I even tried operating for 3 weeks with no stop/resync, but couldn't improve the target SNRM. That was fine tho. But experimenting again with a Billion 5200 showed that I could get up to 2300 at hardwired SNRM 6 during the daytime, and if I rebooted at the worst time of evening, would give a stable 1800-1900 which would hold until a power cut. But as I rarely use the system after 16:00, this week I tried shutting/powering down at that time, restarting the router at around 7am and getting high speeds thru the day - even at the target SNRM of 15 (which the Billion force-lowered to 6-6.5). Thats where I am now, 2080 at 7.0, waiting for the BT profile to increase from pre-Billion 1000 to hopefully 1750, but the Plusnet 'stuck' profile of 750 is hindering. I've just raised a ticket to get it unstuck.
Error rates are OK, downstream power is 16.5, bit-loading is brilliant for my line - 590 bits in 92 tones, whereas best pre-powerleadfix was 440 in 80 tones.
Regards,
Jack
Laser
Grafter
Posts: 206
Registered: 23-09-2007

Re: Just how are profiles applied?

Quote from: Anotherone
Quote
there is a BT-applied speed profile (the BRAS) which is derived from your sync speed. The portal page "high speed broadband" reports this figure, but may be slightly out of date.
True - but it also controls your throughput. eg. if the BT one was 5000, and then PN was still at 1000, your throughput would not exceed 1000.

Given Jack21's experience and since you are a forum Bright Spark, I thought I would look up some background. I've just found confirmation of this. I apologise, I was incorrect.
First I've known about it though!  Shocked

Quote
You previously said
Quote
The BT BRAS profile is set by BT and is always a little lower than your lowest recent sync rate. It's a highly contentious issue because there is no justifiable reason for it,
There is a justifiable reason as I explained. The contentious bit is the time the BT profile takes to recover.

I don't want to get into a bootless argument over this, so I'll delete the reply I just typed and settle for the statement that LLU providers seem to manage without it...
dick:green Link fixed.
Community Veteran
Posts: 19,101
Thanks: 443
Fixes: 21
Registered: 31-08-2007

Re: Just how are profiles applied?

No, don't delete anything, not everybody understands everything including me Wink, apology excepted no problem Smiley. Hopefully those reading here will end up with a better understanding. I agree with you about LLU - just look at what BT are doing to ADSL2+ Cry but don't continue that here , there are plenty of threads over on the ADSL2+ board. Shocked
jack21
Grafter
Posts: 180
Registered: 25-02-2009

Re: Just how are profiles applied?

Hello Anotherone and Laser, and hopefully Plusnet,
There's another small mystery re profiles; the question as to exactly how the sequence/timing of their application goes.
I'd understood it to be that the Exchange would set the BT profile (a) downwards if the sync rate dropped below the prevailing rate-band for more than a few seconds, tho it might take a few hours to make the change, and (b) upwards if a higher rate-band was maintained/improved for a period  between a day and 3 days.  Furthermore, that the Plusnet profile followed the BT profile quite quickly (within a few hours).
However, since I took to powering-down my modem at night, although the BT profile continues as I'd understood (it has increased from 750 some days ago, via 1000 for a day or so, and finally to 1750 (where it remains now, reflecting the 2080 rate which has prevailed) , the Plusnet profile hasn't followed the BT profile - it remains firmly rooted at 750.  I raised a ticket to get the Plusnet profile unstuck, but have been told by Support that I must leave my modem switched on for 72 hours in order for the Plusnet profile to be updated, and that BT (why BT and not Plusnet?) won't correct the problem till thats done.
That sounds odd to me; if the BT profile has calculated/updated correctly, and the Plusnet one is merely a 'copy', I wonder why Plusnet requires the 72 hour wait, when BT doesn't?
Regards,
Jack
Community Veteran
Posts: 19,101
Thanks: 443
Fixes: 21
Registered: 31-08-2007

Re: Just how are profiles applied?

I suspect that the agent that told you that didn't fully understand. As your BT profile is up the PN one should follow.
It hasn't, and is therefore clearly stuck. Hopefully someone from the Comms team will see this shortly and correct the matter. (And perhaps look at the ticket on your account and arrange for the agent to be educated more on the topic).
Community Gaffer
Community Gaffer
Posts: 17,663
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Registered: 05-04-2007

Re:Just how are profiles applied?

Anotherone is quite correct in how profiles work. Your connection is assigned an IP Profile on the exchange equipment, this then gets sent to us via a report and your profile on the portal should match the IP Profile.
If these are misaligned they should realign within 12 hours but sometimes don't catch up. I'll go check your account and make sure they do match now.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff
jack21
Grafter
Posts: 180
Registered: 25-02-2009

Re: Just how are profiles applied?

Excellent, thank you Chris for your intervention.....Plusnet profile now at 1750 matching the BT profile.
Thank you also, Anotherone and Laser for your advice - much appreciated.
Regards,
Jack
Community Gaffer
Community Gaffer
Posts: 17,663
Thanks: 656
Fixes: 162
Registered: 05-04-2007

Re:Just how are profiles applied?

No problems, glad to help.
If this post resolved your issue please click the 'This fixed my problem' button
 Chris Parr
 Plusnet Staff