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Reset SRN - instantaneous or delayed

EnglishMohican
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Reset SRN - instantaneous or delayed

I'm guessing that on a 21cn ADSL2+ line, the card in the exchange that my modem talks to remembers the previous SNR setting that it was working at. and uses that as the starting point when it negotiates the sync speed when I re-connect.
I believe Plusnet CS can reset this figure themselves - without asking BT to do it for them.
So - my question is - when the guy in PlusNet CS pushes the button, does the memory in the card in the exchange forget its setting immediately - or is there some sort of delay built in - several hours perhaps.
Note that I am not talking about the SNR that the line is actually running at assuming I am connected when he pushes the button. I can quite believe that I need to disconnect and re-connect before the system will reset itself using the new (reset) value stored in memory.
If any of this makes sense, can somebody confirm whether it is correct or not please?
For information - the significance of this is that Plusnet said that they reset my SNR today - and then they triggered a disconnect/reconnect. If the reset is instantaneous then I am now running with a reset SNR and at my "best" line speed - if it takes several hours to reset then I need to disconnect/reconnect sometime in the future to take advantage of the reset SNR. I would have thought it was instantaneous but CS said I would have to wait 24 - 72 hours to see my (synch) speed increase. I would like to be sure I know what I am talking about before I tell them that they do not.
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Plusnet Help Team
Plusnet Help Team
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Re: Reset SRN - instantaneous or delayed

Hi there,
Quote
I believe Plusnet CS can reset this figure themselves - without asking BT to do it for them.

Not exactly, we can request it ourselves but that is done via a BT system.
Quote
does the memory in the card in the exchange forget its setting immediately - or is there some sort of delay built in - several hours perhaps.

No, when we make SNR requests they can take up to 24 hours, some people do notice a difference immediately on occasion, most will see the line starting to retrain after about 2 hours. My advice to you is to wait 24 hours before doing anything and yes they are right in saying 24-72 hours, that's the lead time we're given.
If this post resolved your issue please click the 'This fixed my problem' button
 Adam Walker
 Plusnet Help Team
EnglishMohican
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Re: Reset SRN - instantaneous or delayed

Thanks Adam - looks like I had most of it wrong. Embarrassed
Two further clarifications though please:-
Your first statement shows how somebody who knows what they are talking about can leave it unclear to those who do not. I guess you mean that you submit an email or similar that a BT person reads and they push the button that makes things happen. But you could also mean that you push a button (I mean an on-screen button - not a physical one) that sets a flag on a BT computer that means that the next time that computer runs its "reset SNR" programme it picks up my line as one of the ones to reset. The first case has human (BT) intervention, the second still fits your description but is totally automated. It would be nice to be clear which you do mean - or if other possibilities exist then to understand the details a bit better.
Secondly - can you explain the SNR reset/retrain process in  a bit of detail. It sounds as if I was wrong about that as well and as if the exchange can change the synch speed  on the fly  without my router needing to be disconnected/reconnected rather than just monitoring noise levels and developing an idea of the "best" SNR margin to apply when a disconnect/reconnect does happen.
It gets very frustrating when working on a ticket with CS to have brief, sometimes apparently contradictory messages from different agents and no understanding of the process they are trying to follow. Occasionally, their response seems to be them taking the easy way out or failing to understand the situation fully. Others agents are very clear but I might conclude that all of them are very good if I understood the process better.  Thus my questions.
Plusnet Help Team
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Re: Reset SRN - instantaneous or delayed

Quote
Your first statement shows how somebody who knows what they are talking about can leave it unclear to those who do not.

Hi there,
Not what I intended but it's hard to know what level of detail to stop at when explaining these things sometimes Smiley
AFAIK, SNR resets can be submitted on an individual or bulk basis, these are requested by an online BT system which is used by ourselves and all other UK ISPs that resell BT Wholesale broadband services. As for BT's side I doubt any of us would know in explicit detail exactly what happens but we know what we need to know which is that the requests are picked up and actioned within 24 hours.
Quote
Secondly - can you explain the SNR reset/retrain process in  a bit of detail.

This depends on whether the line is 20CN or 21CN for the former the line retrains to a default 6db SNR ratio and a maximum line rate of 2mb, following that the line rate is calculated via DLM (dynamic line management) in the same manner as when a line is newly activated for broadband. As for the latter its the same but we have options to apply specific speed "bandings" and certain SNR levels, thus allowing us to configure a more specific reset to suit the line's characteristics or fault conditions.
Quote
It gets very frustrating when working on a ticket with CS to have brief, sometimes apparently contradictory messages from different agents and no understanding of the process they are trying to follow

Understood, that's obviously something we don't want to happen either. In all honesty I don't think that's happened in your case but would urge you to let us know if you think it has.
If there's a higher reason that you're concerned about this just let me know and I'll do what I can to step in and help.
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 Adam Walker
 Plusnet Help Team
EnglishMohican
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Re: Reset SRN - instantaneous or delayed

Thanks again Adam.
Quote
If there's a higher reason that you're concerned about this just let me know and I'll do what I can to step in and help.

I suppose that is the problem. I do not know whether there is a higher reason or not because without understanding what can be done, I cannot asses whether it has been done in which case all's well or whether I am being short changed. So I am asking questions on here to try to determine what is reasonable for Plusnet to do and what is not.
You may be aware that I have a ticket open at present. I think that all of the responses are rather slow, in some cases it is taking 24 hours to answer a simple question. None of the responses provide a clear adequately detailed explanation of what they are attempting to do, just an idiot's summary.
Far more importantly, some (most) of your engineers reply positively, appear to understand the problem and to be doing what they can to clear it up. A few seem to be doing as little as possible, to have not read the ticket properly, to be simply responding to the most immediate result and to be doing their best to fob me off and close the ticket. That conclusion may be utterly unfair but without a "proper" response, how do I know? I have to judge by the feel I get from the answer, sometimes it's good - sometimes it's not.
So far, the engineers have tried to close the ticket twice. On both occasions I have kicked back and asked questions about what they have done. In neither case has the question been answered but they have gone away and done something else and the situation has improved each time (that is rather over simplified).  One engineer said that 5Mbps was OK because 17Mbps was only an estimate. I view that as interpreting the mathematical science of estimates utterly unreasonably. 16.5Mbps is a reasonable achievement against an estimate of 17Mbps, 17.5Mbps is even better but 5 is no where near.
I am happy to let the Ticket run a bit longer as it is - but if you can give it a push that might be magical
(Edited 21/6/12 to correct my quotes)
jojopillo
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Re: Reset SRN - instantaneous or delayed

Hi EnglishMohican,
I Appreciate what you say but what you have to remember is it's only an estimate, there's no guarantee from BT of that speed. Your attenuation is 32dB, so the speed you're currently getting is consistent with that. The BT availability says, "Our test also indicates that your line currently supports an estimated ADSL2+ broadband line speed of 17Mbps; typically the line speed would range between 10Mbps and 19.5Mbps" and as the line speed does fall between 10-19.5Mbps - which I agree is a large estimate - it's the type of thing that would be pushed back by our suppliers as falling within estimates.
Jojo Smiley
EnglishMohican
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Re: Reset SRN - instantaneous or delayed

Hi JoJo,
Since I typed my last message J has been in touch from the BOT and has done a reasonable job of convincing me that BT do not know what they are talking about and the 17Mbps is just a stupid error on BT's part.  I am not sure what OFwhatever  would say in that case but I will let  that be somebody else's problem. I am going to see what line speed we achieve over the next couple of weeks and go back to him if the line is unstable which was my original problem.
However ....
Quote from: Joanne
......... and as the line speed does fall between 10-19.5Mbps - which I agree is a large estimate - it's the type of thing that would be pushed back by our suppliers as falling within estimates.
Jojo Smiley

....since when has 5mbps been in-between 10Mbps and 19Mbps? It must be a miracle of modern science Grin
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Re: Reset SRN - instantaneous or delayed

der um, is that 5Mbps the sync speed or the download speed?
EnglishMohican
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Re: Reset SRN - instantaneous or delayed

That 5Mbps is the synch speed (Currently 5752 as I write)
There are actually two problems here. Firstly, BT say my line should run at 17Mbps (alright that is an estimate but as JoJo says it should be between 10 and 19 if we believe BT.) However, nobody at Plusnet appears to believe BT - and they may be right, I do have quite along line and 17Mbps seems pretty fabulous to me as well. BUT it seems to me that Plusnet use the BT estimate as a defense when it suits them and choose to ignore it when it does not. Somebody should be making BT either apologise and admit their mistake or produce a line that runs at the speed BT say it will.
The second problem is that my line suffers a lot of intermittent interference. The interference seems to be bad at roughly 3 or 4 day intervals - (no strong pattern but on average) So on ADSL1  I permanently sat with a target SNR Margin of say 12db and an actual SNR of close to  12 db most of the time. So my synch speed was low because of the high safety margin but the time constant of 3 days to step the SNR margin down was just wrong. It would try to step down but then some interference would come along and push it back up again. So for an hours worth of interference every three or four days, I suffered permanent high margin and low speeds. I started the ticket referred to above to try to get something done about the interference and I have been sidetracked into changes to 21cn and ADSL2+ which have all improved the synch speed but how long will it last. J, the Plusnet engineer who phoned me was determined that it would all be wonderful and rather ignored my concerns. He seemed honest so he may be right so that is why we are waiting to see what the system achieves over a week or so. He thought that 7 or 8Mbps would be very good for my line - but that brings us back to do BT know what they are talking about with their estimate.
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Re: Reset SRN - instantaneous or delayed

Your problem on 20CN is that it took the DLM up to three days to change the IP Profile. On 21CN the IP Profile is set to 88.2% of the sync speed immediately after you reconnect, so in a case like yours where you get bursts of interference every three or four days you should be better off. If you get a low speed resync, monitor the noise margin and when it has stabilised at a high level (above your target noise margin), if you do a disconnect and then force a resync you will immediately get the appropriate IP Profile.
The problem for you is that there is often a delay in the PN Current line speed being set to match the IP Profile (and sometimes it doesn't happen at all). In that case you need to either contact CSC or post on here to ask for it to be reset.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
jojopillo
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Re: Reset SRN - instantaneous or delayed

Hi EnglishMohican,
Firstly, I must wholeheartedly apologise for my previous post, I must have been looking at another line (multitasking blonde moment fail) The thing that strikes me is the estimate, yet it's showing as your attenuation is 43dB. If the attenuation really is that then the availability checker is wildly wrong, and that's not good.
Can you tell me if you're using any extension cables/sockets? Do you have a test socket you can plug into?
Jojo Smiley
EnglishMohican
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Re: Reset SRN - instantaneous or delayed

Hi Jojo,
The filter is plugged into the test socket- yes, I mean the one behind the faceplate of the master box and it has been so plugged for 18 months now. The router goes into one side of the filter and a phone splitter goes into the other socket on the filter. That then connects to a local hard wired phone and to a dect transmitter for the walk about phones. The Dect transmitter is sited reasonably far from the router (supplied wire length) and the router wireless is not used but a separate air-point is connected to the ethernet ports on the router and placed as far as the cables will let it be from the router itself.
There is no extension wiring connected.
The filter is new (2 weeks old) and the router I am using at the moment is new. The same sort of problem (the ADSL1 version) applied using the previous router and filter. On the old router, the wire from the filter to the router was about 18 inches long. On the new router, I am using the supplied cable which is bundled up, not coiled.
In summary, it's all wired up as well as I know how to do and the 43db is not me gov'nor.
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Re: Reset SRN - instantaneous or delayed

Quote from: Joanne
............ (multitasking blonde moment fail)................
ah bless her, she does work very hard so you've got to forgive her  Wink  Kiss
Quote from: EnglishMohican
............ and the 43db is not me gov'nor.

waz mean? not you  Roll eyes  From  a couple of previous posts I see you've mentioned 43dB and more recently 41dB both on 20CN, so 43dB on 21CN would be about right. So, if all things were equal, you ought to be able to get around 9 or so Mbps.
EnglishMohican
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Re: Reset SRN - instantaneous or delayed

Quote from: Anotherone
waz mean? not you  Roll eyes  From  a couple of previous posts I see you've mentioned 43dB and more recently 41dB both on 20CN, so 43dB on 21CN would be about right. So, if all things were equal, you ought to be able to get around 9 or so Mbps.

Waz mean = I am not the cause of it.
I agree that it is the right figure for my line, 43.7db at this instant - but it is not my extension wiring that is causing it because  there is no extension wiring.
You say 9Mbps, PlusNet say something similar, SamKnows says much the same but BT say:-
"Our test also indicates that your line currently supports an estimated ADSL2+ broadband line speed of 17Mbps; typically the line speed would range between 10Mbps and 19.5Mbps."
I like the BT answer -and they should know what they are talking about Wink
And no, 9 is not nearly 10 - 10 is a once in a few thousand absolute minimum.
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Re: Reset SRN - instantaneous or delayed

Quote from: EnglishMohican
I like the BT answer -and they should know what they are talking about Wink

You have proof of this  Grin Grin Grin
Computer say no  Wink