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[Weaver]

For some reason, two of my three modems have decided to go above 2300 d/s sync rate. The third modem is sitting right on the threshold for 2000 d/s IP, which is 2272. The speed testers’ reported d/s values went up by >0.5 Mbps in total. The most optimistic tester, the speed-test website speedof.me recorded a record-breaking 6.03 Mbps d/s plus half a dozen readings at or above 6.0. This is 0.53 Mbps higher than anything ever recorded before this week. I have absolutely no idea why this is happening so suddenly. The third line could very well break through the d/s IP2000 barrier too given time, as it has not had long enough at the 2272 d/s sync rate yet.

This means that the DLink DSL-320B modem is now an all time record breaker, top dog, holding on at something around the records achieved but not sustained by the Netgear DG834v3. I am going to compare the Draytek Vigor 130 modem against this current champion.

Upstream hit a record of 0.99 Mbps too. This is due to u/s sync rate changes, and me pushing the traffic shaper fudge factor slightly harder, changed to 0.8880 from 0.8800, it is amazing that such a tiny change has a readily measurable effect.

Having an additional 0.6 Mbps compared to this time last week is very pleasant. I have also noticed that pushing the u/s slightly harder by setting the Firebrick's traffic shapers to very slightly higher values does improve the _d/s throughput_ for some reason. [Currently set to = 0.888 × reported u/s sync rate ]. Getting the ACKs back slightly sooner?

[burakkucat]

  b*cat gets excited waiting for news of the latest tweak. 

(You actually have better DS & US rates than that available on the circuit which feeds The Cattery!)

[Weaver]

I just have no idea why this improvement to d/s sync rates has happened. The d/s SNRM is where it should be, on 6-7 dB. Weather has been nasty for the last six days, gales at the end of last week, predicted 90mph winds never happened up here, it was blowy, but nothing much by Skye standards.

[Weaver]

And now still further improvements, to 6.23 Mbps downstream. (As measured by the speed of.me tester website

[burakkucat]

And now still further improvements, to 6.23 Mbps downstream.

I wonder if it is the ever-present threat of winter-time atmospheric electrical disturbances that has prompted your combined circuits to provide just that little bit more? 

[Weaver]

I have no idea why this has suddenly happened, but the threat of lightning strike (warning from the new device) prompted my beloved to nip into the office and abruptly disconnect all three modems from the wall sockets, without turning the modems off first. My wife is accustomed to switch the modems off first every time before pulling cables out of the wallsockets, in case last gasp / dying gasp or whatever should prove beneficial - although our leader, Kitz, suggests that BT ignore last gasp. But anyway on this one occasion, Janet pulled the cables straight out, which might be considered a bad thing, the result though was that all three modems were above 2272 d/s sync rate, indeed one was in the ~2400 range.

Andrews and Arnold list them all as 2.27 d/s band (which presumably means roughly ATM bit rate), which has never ever happened before. Can only hope to goodness that this is sustained, I will have to offer a libation to the gods, as this is after all St Andrew's Day.

[tickmike]

Has your exchange gone over to 21CN ?, When mine went over last year I got a small increase.

[Weaver]

> Has your exchange gone over to 21CN ?, When mine went over last year I got a small increase.

Would that mean I am running in ADSL2 or ADSL2+? I would certainly expect a speed increase from ADSL2.

It is due to change over from 20CN to 21CN so I have been led to believe (in an email from Highlands and Islands Enterprise), but I was expecting it to be a little bit later.

I don't know how to tell. Andrews and Arnold think it's 20CN anyway, from the following
--
For line #1 of 3:
BT 20CN ADSL Premium
01471 123456 No chargeable outgoing calls allowed (business grade line)
Standard care on DSL service
Standard stability line setting
Interleaving on

BT Test xDSL Status Check:Pass OK.pass OK. Circuit In Sync
BRAS=2000Kb/s FTR=1817Kb/s MSR=2272Kb/s ServOpt=1 I/L=I
Up Sync=416Kb/s LoopLoss=38dB SNR=7dB ErrSec=6 HECErr=1 Cells=119952
Down Sync=2400Kb/s LoopLoss=63.5dB SNR=6dB ErrSec=0 HECErr=0 Cells=996264
--

I do hope they have got this right as they should be halving my daytime download costs from 1.25 GB per unit under 20CN to 2.5 GB per unit under 21CN (where a unit is currently ~£3.90, a charging unit).

[burakkucat]

I don't know how to tell.

The US synchronisation speed is a good indicator.

BT Test xDSL Status Check:Pass OK.pass OK. Circuit In Sync
BRAS=2000Kb/s FTR=1817Kb/s MSR=2272Kb/s ServOpt=1 I/L=I
Up Sync=416Kb/s LoopLoss=38dB SNR=7dB ErrSec=6 HECErr=1 Cells=119952
Down Sync=2400Kb/s LoopLoss=63.5dB SNR=6dB ErrSec=0 HECErr=0 Cells=996264

That looks very much like 20CN to me.

[Weaver]

There is no US 448 k cap, as this is "premium" btw. And it is of course a ridiculously long line.

[Weaver]

All three modems are now hitting those kind of sync rates at the same time, that's the cause of the latest (second) breaking of speed records.

[off-topic]
btw: Notice what a load of old nonsense the MSR is (and so therefore the FTR) because it's actually lower than the current d/s sync rate.

I wonder why it isn't automatically set?

[aesmith]

btw: Notice what a load of old nonsense the MSR is (and so therefore the FTR) because it's actually lower than the current d/s sync rate.

Surely by definition MSR will always be lower than your best sync rates, since in BT double-talk "Maximum Stable Rate" actually means Minimum.   Aside from that one ISP support guy told me he sees loads of lines with those figures 2272/1817 on lines where they make no sense at all, he thinks that's some sort of default.   We have the same figures, and they're dated 7 days before our service went live, so clearly not based on any measurement.

[roseway]

MSR and FTR are explained here: http://www.kitz.co.uk/adsl/maxdsl2.htm

[sevenlayermuddle]

On 20cn, if you want to have MSR and FTR recalculated, I believe you can (could at one time) do so by persuading your ISP to request a process called CCSNR reset, 'Customer Controlled Signal to Noise Ratio reset'.   

Afaik, it is intended for situations where circumstances have changed, such as an improvement in line conditions, and it effectively restarts the initial line training process all over again including resetting target margin and recalculating MSR/FTR.    It always struck me as being of limited use, as many/most ISP's helpdesks would reply 'A what?'.  But Weaver being AA, we could hope for better..?

Forgive me however if that suggestion is obsolete, I don't recall hearing of it for some years gone by.

[Weaver]

@sevenlayermuddle  - Being AA, there might indeed be a chance, as they (i) will know about it, and (ii) might even give a stuff.

I had my line put back into the training phase by A & A earlier this year, but perhaps that was a lesser procedure, and the procedure that sevenlayermuddle refers to includes the one applied to me.