Possible to return to 1Mb fixed from MaxDSL?

I have been with Plusnet for 5+ years, the last 3-4 years at my current address.
I was initially told I could not have broadband, since I was right on the distance limit from the exchange for receiving 512k.
Nevertheless, Plusnet agreed to connect me, and I was able to obtain around a 400-500K service. Sometime later, my speed increased to around 900k which I started to achieve reasonably consistently for over a year.
Then, about 6-9 months ago, my connection speed dropped to around 300-400k, a dramatic drop!
This coincided with a move to MaxDSL with Plusnet.

Apparently, I am told that the maximum sustainable rate is measured as an average over a three day period, and this is forcing me onto such a low speed.
I don't understand exactly how this works, but suspect that the max. possible speed is checked each day, and based on the average of three day's checks, I am allocated a 'constant' rate. This rate changes slightly each day, as the 3-day average is re-calculated.
However, I'm guessing that a downside is that even if a high rate was achievable, because it is not constant, the daily checks could be recording the periods of low speed.

Of course I would rather go back to my previous situation where I was getting a near constant 900k speed. I suspect in reality, I was achieving 800-900k, but not constantly. It probably dipped to 400k from time-to-time.

However, I would much prefer a 'near-constant 900k, to a completely constant 400k!

Is it possible to return to my previous service 'up to 2M' from my current MaxDSL. Plusnet previously advised that I would NOT get better speeds, and that MaxDSL is better. Indeed they are saying that 512k is the best I could achieve on a fixed-rate service.

I accept that this is what is shown on any line-checker.
However, it has always said this, yet I was able to achieve 900k+ for over a year without any major issue. I believe Plusnet had connected me to a 1Mb fixed service, and I was achieving a reasonably constant 900k rate. Am I right to believe that even if they connected me to a 1Mb fixed service, if the line couldn't maintain that rate, I would just experience whatever level it 'could' maintain. So I 'may' achieve a fluctuating service between 400-900k. Surely this is better than a 'constant 400k'....?

Line noise is 63dB which I don't think I can improve.
The only change in my house (since the days of achieving 900k) are that I am now connecting direct through the main socket (behind the faceplate), and a single phone is connecting to the same socket (through a filter). No other telephone sockets are being used in the house (although one other socket 'was' in use when I was achieving a 900k rate).

You're idea of how Max works is wrong.

The modem will always connect at the fastest speed possible where it can meet the target noise margin. To see what is happening and explain more some stats from your ADSL modem i.e. attenuation, noise margin and connection speed are needed.

If it entirely possible to have the modem connecting at 1152Kbps most of the time, but the odd slow connection causes a setting called the IP Profile to drop, and this takes between 75 minutes to 5 days to recover to a higher setting once the modem reconnects at a better speed.

If this flapping occurs a lot the target noise margin figure is increased which reduces the maximum possible sync speed, which should improve stability, i.e. less flapping around of the speed.

If line noise was 63dB you would be the first in the world, that would be the attenuation you are quoting, and this is the most the modem can display, so the real figure may be a lot higher, time to find the noise margin and precise line sync speeds.

With a 63dB margin you are outside the limits for a Home 1000 fixed speed service, and if your line is wandering around a lot, putting you on a fixed 1Mbps Max profile may not help either, a fixed 0.5Mbps might.

If the speeds are worse since you changed something, go back and set things back to what they were and if that is better then use it that way.

Thanks for the quick reply :-)

Obviously you were right, in that I was quoting the attenuation at 62dB.
My full ADSL status information, taken from the modem, is as follows (although I don't understand the significance of much of it).

Interleaved Channel Fast Channel
Data Rate Data rate

Up Stream 280 Kbps 0
Down Stream 1728 Kbps 0

Upstream Downstream

Noise Margin 6 dB 10 dB
Output Power 12 dBm 17 dBm
Attenuation 31.5 dB 62 dB


You say
"If this flapping occurs a lot the target noise margin figure is increased which reduces the maximum possible sync speed, which should improve stability, i.e. less flapping around of the speed. "

If I understand correctly, the result is that I have excellent stability, but at a rate of approx 400K.
Is it not better to have 'less' stability, but a rate ranging between 400-900K ?
What is the benefit of stability?
Should I really care if sometimes my downloads are only achieving 400k, whilst at others I might achieve 700k, or 800k or 900k etc.?
At the moment I am achieving a 'stable' 400k. ie. 'never' achieving more than that.

I appreciate that with 63dB I should be outside the limits for 1Mbps, but this hasn't changed for years, yet I was able to achieve near-1Mbps performance for over a year. (Again, I admit that it may not have been a 'constant' 900k, but when I was checking twice daily, I achieved 800-900k at least 75% of the time.)

Is there a downside to me being put on a fixed 1M service?
The cost is the same as what I am paying now.
At best, I 'might' achieve 900k again.
At worst, I would achieve whatever rate my line is capable of achieving, which may only be around 400k.
I'm assuming that being put on a 1Mbs service would not cause my connection to be sub-optimal eg. sub-400k?

(The ONLY think that has changed since the time I was achieving 900k connections, is that 'now' I do not use any extension sockets in the house - I only use the single main socket. I'm assuming that if anything this would improve the quality. It certainly shouldn't reduce the quality of the line.)

Cheers,
Don

Hmmm.....my data got un-formatted...

Trying again, with a different layout, hopefully easier to read...

Interleaved Channel Data Rate:.....UpStream=288Kbps.... Downstream=1728Kbps
Fast Channel Data Rate.............. UpStream=0................ Downstream=0


Noise Margin:... Upstream=6dB........ Downstream=9.5dB
Output Power:..Upstream=12dBm.... Downstream=17dBm
Attentuation......Upstream=31.5dB.....Downstream=62dB

All Plusnet accounts are now "up to 8MB".

What I think you are confusing if the old fixed 512, 1M and 2M connection speeds and MaxDSL which is "up to 8MB" and can in practice mean anything from almost dialup speeds to 8MB.

It sounds as if you were on the fixed rate 1MB. I suggest you ask to be put back on to that.

Down Stream 1728 - 1.7Mbps - now keep an eye on this, does it alter a lot?

You should have a 1.5Mbps IP Profile if you maintain that sync speed long enough.
http://www.thinkbroadband.com/faq/sections/radsl.html#225

WIth a 10dB margin I'd hope the line would remain stable, if it is not then time to look at the extensions in your property and unplug everything and test using the master socket and its hidden test socket. NOTE speedtests will take a long time to improve but the sync speed and other data you've just supplied should change maybe.

"Is it not better to have 'less' stability, but a rate ranging between 400-900K "
If this instability means the modem is dropping the line and reconnecting ever 55 minutes - would that be good?

Pay a visit to www.speedtester.bt.com and paste the results you get back - this tells you your current IP Profile.

Your line is connected currently at speeds in excess of 1Mbps, now you may have speedtests giving results at 400Kbps, because you had an occassional low speed sync which lowers your IP Profile setting, so time to find out what that setting is.

"Is there a downside to me being put on a fixed 1M service? "
Yes, if your line is wandering around with sync speed now and connecting at say 768Kbps sometimes, on a fixed speed service you would not connect at all. Willing to go without ADSL for a few hours a day perhaps?

The noise environment in the range ADSL users is an ever changing feast, so what speed you connect at one day may not be the speed you connect at another.

One final note...you are connecting with an upstream speed of just 280Kbps which is somewhat low and suggests you may have something plugged into the line with no microfilter, or so many telephone extensions that the noise pickup is high, or a dirty connector, or just something that is electrically noisy in the vicinity.

This is all excellent advice and information, and I greatly appreciate it.

Regarding this sync speed (currently showing 1728Kbps) I am taking the reading from the modem's 'ADSL Status Information' page - I'm using a Belkin wireless modem/router if that is of any interest.

How often is this figure sampled? Is it continuous, or checked periodically, or just each time I connect? It's still reading 1728Kbps now (having refreshed the web-page) and appears to have been static all-day at that figure. However, I have not disconnected/re-connected my line. Indeed I never do on purpose, although periodically - maybe once every 2 days - my connection seems to 'lock' and I re-boot the modem. (When I say 'lock', the connect lines are still lit suggesting I am still connected and synced, but am unable to access any web page. Re-booting the modem enables a re-connection and I can then access the internet).

Anyway, I will check and record this figure every hour for the next few days to see if it changes.

Regarding extensions, although I have 5 'built-in' extensions (house is only 4 years old) none of them are currently in use. I have no other phones plugged in, no sky etc. I only have a single microfilter plugged into the hidden test socket (I have removed the faceplate from this master socket) into which I have plugged in the modem, and the house's single phone. (I used to have this phone plugged into an extension, but was advised by Plusnet to plug it into the main socket, which I did recently - it has made no difference to my 400k connection.)

Wow....I have finally managed to access the bt site.....
I get the following:
Test1 comprises of Best Effort Test: -provides background information.
IP profile for your line is - 1250 kbps
DSL connection rate: 288 kbps(UP-STREAM) 1728 kbps(DOWN-STREAM)
Actual IP throughput achieved during the test was - 409 kbps

Hmmm...this is looking promising...I think....

Though not sure how to proceed. Obviously contact Plusnet, but they simply refer to my 62dB attenuation and say I cannot achieve better than 512K.

Any advice appreciated :-)

Cheers,
Don

Don,

Can you do me a favour and PM me your username?

I just want to check if we're profiling you correctly.

Thanks. I did ask, back in December. They said 'no'.

I believe I was on an 'up to 2Mb' service about to about 6 months ago, and was reasonably happy with my 900K connection speeds (bearing in mind my distance from the exchange).

However about 6 months ago, which I believe coincided with the move to MaxDSL 'upgrade', my connection more than halved to the current 400K.

You will see from my other posts in this thread that Plusnet appear to have me on an IP profile of 500K - though not sure if that means I am limited to 500K max.

Am currently contacting Plusnet to investigate.

Cheers,
Don

The sync speed you get is negotiated on connection and under the BT ADSL system it will not change unless the line resyncs (disconnects and reconnects). Does your router have a WAN uptime? If so then it should be possible to tell a resync event occuring from this (even if the resync is to the same speed as before).

Since ur BT profile is now 1250Kbps, what is your PlusNet profile speed (I think it is called My Broadband Speed or something like that in the member centre). If this is different then PN are still waiting on BT to supply them an update so they can raise the profile their end.
Also it is possible your exchange is very busy, although BT tests at various times of day should show speed changes (typically you would expect fastest in the middle of the night and slowest in the evening unless you have a very business orientated exchange when the busiest could be during the day).