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Fibre bump requests.

22over7
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Registered: 07-04-2016

Fibre bump requests.

BT (wholesale) have a "profile" for your line.  Plusnet have a "profile" on top, or so I understand. This seems to cause problems when the Plusnet one is needlessly more severe than the BT one.  So there are many requests in this forum for speed bumps,without much forum value. 

 

So, the modem syncs at  dS Mbps, reports its attainable as dA, the BT profile or "BRAS rate" is dB, and the plusnet profile is dP.

For information:

1. What formula says: a profile bump is worthwhile? Are there any other numbers relevant? 

2. Why is there one profile on top of another?

3. Various "faces", Gandalf etc graciously administer these bumps. Why do they have to be asked to do it in a forum, where nobody really learns anything from it? Is there not some better way, like just having one profile?  Or an algorithm? Or explaining why there are two "profiles", and what this accomplishes?

 

 

 

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Plusnet Help Team
Plusnet Help Team
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Re: Fibre bump requests.

Hi there.

 

So, the modem syncs at  dS Mbps, reports its attainable as dA, the BT profile or "BRAS rate" is dB, and the plusnet profile is dP.

The Plusnet profile (known internally as the connection profile) should match the IP profile. When there's changes to the sync speed/IP profile, it should automatically update via something called a delta report.

 

1. What formula says: a profile bump is worthwhile?

From time to time, the connection profile doesn't update automatically or is a bit slow.

So if this profile is set too low and it's restricting throughput, we'd manually adjust it.

 

Are there any other numbers relevant? 

I don't think so.

 

2. Why is there one profile on top of another?

I believe the connection profile is part of our traffic management system.

 

3. Various "faces", Gandalf etc graciously administer these bumps. Why do they have to be asked to do it in a forum, where nobody really learns anything from it?

You can ask us to update the connection profile via any means of support. Phone, Live Chat, Social Media, Ticket etc.

I think it seems that people request it more via the forums as it's more of an open space here. For example, most of the other methods of support are more 1 to 1.

 

Is there not some better way, like just having one profile?

I agree.

 

Or explaining why there are two "profiles", and what this accomplishes?

As the connection profile is essentially part of our traffic management system, which is still in place for some types of accounts, removing it isn't something we can do.

 

Since moving migrating users from the WBMC Shared (L2TP) to WBMC Dedicated, our profile tends not to restrict throughput due to how connections are routed across our network.

With that said^, those with static IP's or on 20cn are still affected by the connection profile.

If you're interested in knowing more, there's more info over here.

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team
22over7
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Re: Fibre bump requests.

Thank you very much Gandalf.  By the way, I found a stonkingly good explanation on the kitz website, here:  FAQs about BT's IP Profile.

 

My sync speed is 79999/19999, my attainable is almost 100Mbps(!), and my BRAS rate is 74.1. Speedtests are about 70Mbps. Can this be right?   That's not a rhetorical question: it's not clear to me.  My line is heavily interleaved (INT 8, INP 52), though quite stable, with few alarming stats.  

Plusnet Help Team
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Re: Fibre bump requests.

No problems, yeah the kitz site is a good resource.

 

My sync speed is 79999/19999, my attainable is almost 100Mbps(!)

It's possible that your line is capable of 100mbps Grin but the sync may be restricted by the FTTC product.

 

and my BRAS rate is 74.1

From testing your line I can see your sync rate is at 76mbps so the BRAS rate is about right.

 

Speedtests are about 70Mbps

That also seems about right, you'd normally always get a lower download speed/throughput than the sync rate as there are overheads of the connection. With that said, was that test done over WiFi or a wired connection to the router?

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team
22over7
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Re: Fibre bump requests.

 With that said, was that test done over WiFi or a wired connection to the router?

 

It was done over wifi, but that is connected at 450Mbps, and has tons more throughput than my FTTC line.

 

I accept what you say.  I find it curious though that my SRNM levels are at over 7 dB. Something is holding these above 6dB. When I set a cap on my own sync rates, my SNRM levels are raised (even higher).  Though I currently have no sync caps, and my sync is the max possible for my broadband, the SNRM  remains stubbornly high. What might that be?

 

Community Veteran
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Re: Fibre bump requests.

A couple of things

A sync rate of 79.99 with a BRAs reported sync rate would indicate that your profile is retransmission high which reports a sync rate rather lower than the actual

The reported noise margin is higher than the default (6dB or 3dB) because the sync rate is limited by the product you are on and the noise margin is whatever it is and isn't controlled

This post shows the effect on my line https://community.plus.net/t5/Everything-else/Can-t-run-the-BT-Speedtester-flash-not-supported-in-my...

0.128M-80M Downstream 3dB, Retransmission High - 0.128M-20M Upstream, Error Protection Off

22over7
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Re: Fibre bump requests.

Thank you oldJim.  I'll certainly look at that link.  I couldn't understand why the modem thought is was in sync with the cabinet at 79.99, while the profile (which for sure is retransmission high) said something lower, corresponding more to the maximum data rate achievable beyond the cabinet.  

A bit confusingly, Gandalf quoted another "sync rate" of 76.1.   What is this?  I can see, clear as day, what my modem is syncing at. How could Openreach's equipment think it was something else? Presumably a modem and a Fibre cabinet have to agree on their sync rate? What *is* a sync rate?

 

Perhaps 76.1 is a kind of max data rate achievable between the modem and cabinet after minimal overheads are taken off?

Then there is an (even lower) BRAS rate (74.1), which as I understand it is something helpful to the ISP, so that the line isn't overwhelmed by too much bursty traffic.

 

 

 

Community Veteran
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Re: Fibre bump requests.

when you read the thread you will see that I couldn't understand it either - and I still don't - but that is the way the system seems to work

The sync rate is measured at the CAB not at the exchange and the cab presumably reports a reduced figure back unless the system does it the other way round with the IP Profile being calculated at the cab and reported back to BTw which then use the standard algorithm to reverse calculate the sync speed. If the algorithm used at the cab is different when it is in Retransmission High Setting and BTw don't know what has been used

Of course I could be talking rubbish

RealAleMadrid
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Re: Fibre bump requests.

This has been seen before, the "sync speed" seen by PlusNet's tests is a fair bit lower than the actual modem sync speed when retransmission high is active, the BT IP profile can be down to 91% of the real sync speed so although the retransmission helps a lot with errors there is a hit in terms of your maximum throughput speed. My around 350 metre line on a small cab syncs at the full rate with retransmission low with an IP profile of 77.35 Mbps (96.7%). It's a shame that the PlusNet line speed profile (which does apply to my line as I have a static IP)  has never updated correctly and is currently rather low at 74.2 Mbps. @Gandalf Any chance of a tweak?

22over7
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Re: Fibre bump requests.

It's a shame that the PlusNet line speed profile (which does apply to my line as I have a static IP)...

I didn't know that. A static IP is very useful for MyDslWebStats, though originally I thought I might make wider use of it.

The conclusion I am drawing from this discussion is that the word "sync" should(but never will)  be reserved for a telephony issue across a copper phone line (or something analogous with FTTP): eg 79.99. "Maximal Data rate" might be another good term, for the amount of data one can stuff down one's error prone line in a burst, eg 76.1. "Sustainable Data rate" likewise for the amount of data one can sustain on ones internet connection, that partly depends on the ISP's arrangement, eg 74.1.  

These quantities (except maybe raw "sync") are extremely squiffy. Finger-in-the-air, rule-of-thumb, not science or engineering. And not just squiffy; complicated, themselves error-prone, and likely to cause problems, work and money.

 

 

 

Browni
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Re: Fibre bump requests.

A static IP is irrelevant with MyDslWebStats, a device within your own network transmits the router stats to the central database, perhaps you are getting confused with the TBB Monitor which did require a static IP?

 

I must have been really bad in a previous life as this was my 3rd ISP in a row that used lithium.
Now you're stuck with me because my new ISP doesn't run a forum Cheesy
22over7
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Re: Fibre bump requests.

Oh well, I don't need a static IP then. Or, wait, doesn't ThinkBroadBand's Quality monitor need it, without something complicated involving DDNS?

 

But why exactly should a static IP require two levels of uncoordinated profiling?

 

Browni
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Re: Fibre bump requests.

Quite simple really, with MDWS you are sending your data to a known address, with TBB, it needs to know which address to ping.

In answer to your 2nd question that's down to how Plusnet route traffic and which gateways are used.
I must have been really bad in a previous life as this was my 3rd ISP in a row that used lithium.
Now you're stuck with me because my new ISP doesn't run a forum Cheesy
Plusnet Help Team
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Re: Fibre bump requests.


RealAleMadrid wrote:

@Gandalf Any chance of a tweak?


Tweaks have been done. Maxed it out to 78000kbps.

Automation should adjust it where appropriate over the coming days.

If this post resolved your issue please click the 'This fixed my problem' button
 Anoush Mortazavi
 Plusnet Help Team
RealAleMadrid
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Re: Fibre bump requests.

Thanks for that.Smiley