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[shape]

Hey thats what i call good service,
Top draw plusnet dude
Wish my Bt contact was that helpful, hiding from me at moment, lol.
 

[guest]

Ermmm those errors weren't that bad given he was caning the line.

Oh well best wait until that's done and hope DLM doesn't kick in (which I think it will now).

I reckon moving the slider in the DMT tool up two or three notches would have made the line rock solid and not dropped sync speed enough to affect the profile.

[kitz]

>> There was a post earlier in the thread linking to PN webspace I figured out the username from there.

ahh - detective parr eh?

Thanks chris

[kitz]

Perhaps its just me then (as long as Im not a gamer) who would prefer that interleaving is applied in the hope that it may help sort the problem.
Interleaving and Target SNR are  2 separate configurable attributes,  Interleaving is normally applied first in an attempt to stabilise.
Unless youre an ardent gamer, most people dont even realise that its on their line.   

If it doesnt then we still have DMT to play with,
or if you think best could always do the DMT tweak tonight?
Then one way or other this could be resolved PDQ?

[guest]

Interleaving won't stop the line dropping IMHO. All it will do is reduce the uncorrectable errors and there weren't that many of them.

As DLM doesn't appear to be functional on that line then the profile wouldn't be reduced if we had a play - correct or not? I haven't a clue personally

If that is correct then I'd recommend upping the noisemargin slider to 120%, saving and rebooting. Then we can see where we are.

Asssuming AL is up for it of course?

[PortyAL]

Interleaving won't stop the line dropping IMHO. All it will do is reduce the uncorrectable errors and there weren't that many of them.

As DLM doesn't appear to be functional on that line then the profile wouldn't be reduced if we had a play - correct or not? I haven't a clue personally

If that is correct then I'd recommend upping the noisemargin slider to 120%, saving and rebooting. Then we can see where we are.

Asssuming AL is up for it of course?

Well, I went for it!

Stats after resync are as follows: (file uploader on forum wouldn't work)

Statistics Downstream Upstream 
 Line Rate 4672 Kbps 448 Kbps 
 Noise Margin 7.4 dB 22.0 dB 
 Line Attenuation 50.0 dB 30.5 dB 
 Output Power 19.3 dBm 12.0 dBm 
 K (number of bytes in DMT frame) 147 15 
 R (number of check bytes in RS code word) 0 0 
 S (RS code word size in DMT frame) 1 1 
 D (interleaver depth) 1 1 
 Super Frames 23759  23757   
 Super Frame Errors 19  0   
 RS Words 0  0   
 RS Correctable Errors 0  0   
 RS Uncorrectable Errors 0  0   
 HEC Errors 12  0   
 OCD Errors 2  0   
 LCD Errors 0  0   
 ES Errors 0  0 

Any comments would be appreciated.

What effect will the interleaving have?

Thanks

AL

[guest]

120% might have been a touch too much but lets wait and see Your noise margin went down to 5.1dB at around 11pm last night so if its around the 7dB mark at the same time tonight then that should keep the line stable. Give it a bit of a hammering overnight and lets see what your error count looks like in the morning. Has your profile changed at all - it was 4500kbps wasn't it?

Interleaving will simply reduce the number of CRC errors - these are uncorrected errors which would require data to be retransmitted. It won't keep the line sync'd IMHO, only the noise margin is going to do that as a resync will occur when you lose framing which interleaving doesn't affect.

If you have the same profile as before then this might be all the tweaking that is required.

Edit - somewhere on the Plusnet site you should be able to see your IP profile. I've only used them "involuntarily" so I have no idea where that would be. kitz will know if you don't.

[PortyAL]

120% might have been a touch too much but lets wait and see Your noise margin went down to 5.1dB at around 11pm last night so if it's around the 7dB mark at the same time tonight then that should keep the line stable. Give it a bit of a hammering overnight and lets see what your error count looks like in the morning. Has your profile changed at all - it was 4500kbps wasn't it?

Interleaving will simply reduce the number of CRC errors - these are uncorrected errors which would require data to be retransmitted. It won't keep the line sync'd IMHO, only the noise margin is going to do that as a resync will occur when you lose framing which interleaving doesn't affect.

If you have the same profile as before then this might be all the tweaking that is required.

Edit - somewhere on the Plusnet site you should be able to see your IP profile. I've only used them "involuntarily" so I have no idea where that would be. kitz will know if you don't.

Profile as per Plusnet is still 4500kbps. Will try a couple of downloads tonight and will report again in the morning.

Excuse my ignorance but do I have to keep the DMT tool running all the time or can I just load it in the morning and do a screen shot?

Thanks

AL

[guest]

Load it in the morning - the error counts are recorded by the router and not the DMT tool.

No need to excuse "ignorance" - the only way to learn is to ask when you don't understand. Only fools stay silent and pretend they understand

I assume that interleaving won't kick in until you reboot the router so we should still be able to compare tomorrow's error count with today's with some degree of confidence.

[guest]

By the way your noise margin will rise during the day - probably to around 8.5-9dB - as there's just less electrical noise around.

kitz - does his router store the DMT tool modifications or is it like the Netgear ones where it has to be reapplied every time you reboot?

[kitz]

Sorry rizla I was always under the impression that it was HEC errors which could cause the loss of sync to the exchange.  The line was also showing Errored Seconds.  BT docs state that they normally apply interleaving first in order to maintain stability.
Since the BT docs also state that unless you sync at the full 8128 (when you can get the reduction to 7616), then interleaving shouldnt really make much difference to the sync speed.
eg SIN 386 states

"Service Providers should consider carefully before selecting this opt-out option, since interleaving offers the potential of significant improvements to the end user service. Without using interleaving to stabilise a line, other methods may be used, which could lead to a reduction of the achievable line rate".

I have certainly seen many users complain about line drops after they've asked for interleaving to be turned off, and have also seen several request for it to go back on again because they got fed up of the line drops. :/

Therefore my reasoning that it couldn't do any harm to at least give it a shot and see if it could help without having to bring his speed down.

>> As DLM doesn't appear to be functional on that line then the profile wouldn't be reduced if we had a play

Unfortunately not - Different processes - see diagram

Not sure what the DLM at the exchange is doing with the target SNR stuff... but the IP profile is obviously still working ok, and he is being profiled at the RAS - it must be working for his last increase to 4500.
The DLM stuff is all dealt with at the exchange. Profile stuff is sent from the exchange DLM (remember "RAMBO"?) over to the RAP to the RAS.

[kitz]

Re the IP profile - the "stable rate" shown on the Plusnet website will always "lag" since BTw report the IPprofile to the ISP via a delta report, and it could take up to a day before its reflected on the portal.

A sync rate of 4672 generates an IP profile of 4000.
A minimum sync of 5088 kbps is needed to get 4500..  which may be a tad too high to retain stability purely using DMT.

>> kitz - does his router store the DMT tool modifications

Not 100% certain with the 2091...  but afaik I don't think it does with any of the v8 routers.
If anyone knows otherwise then please let me know.

[guest]

Ah I thought it was (at most) 250kbps increments. Lets see what's happened to his error count this morning before anything else is tried.

Edit - re line dropping : I didn't explain that well. Yes HEC helps prevent loss of framing but he wasn't having anywhere near enough CRC errors to indicate that dodgy headers were occurring in sufficient quantities to cause LoF so from that I deduce his problem of a twice-daily resync is a local impulse noise source. Interleaving won't fix that - only increasing the noise margin will. Hopefully that makes sense.

[PortyAL]

Hi

Connection dropped again during the night. I connected again this morning. Stats are as follows:

Line Mode G.DMT   Line State Show Time 
 Latency Type Interleave   Line Up Time 00:04:55:37 
 Line Coding Trellis On   Line Up Count 36 
   
 Statistics Downstream Upstream 
 Line Rate 4832 Kbps 448 Kbps 
 Noise Margin 8.0 dB 21.0 dB 
 Line Attenuation 50.0 dB 30.5 dB 
 Output Power 19.6 dBm 12.1 dBm 
 K (number of bytes in DMT frame) 152 15 
 R (number of check bytes in RS code word) 16 16 
 S (RS code word size in DMT frame) 1 8 
 D (interleaver depth) 32 4 
 Super Frames 1043375  1043373   
 Super Frame Errors 44  0   
 RS Words 70949568  8868670   
 RS Correctable Errors 11935  0   
 RS Uncorrectable Errors 731  0   
 HEC Errors 41  0   
 OCD Errors 1  0   
 LCD Errors 0  0   
 ES Errors 0 


AL

[guest]

It didn't drop. You got disconnected due to the interleave order placed by Plusnet.

Did you reboot the router to connect?