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[NewtronStar]

It has been a long journey for me to find why my line has never been moved to fastpath on the DownStream side it's nothing to do with Errored Seconds or CRC's or a high SNRM it looks like it's down to FEC counts and I have said in past FEC (forward error correction) is a good guide to see the level of noise on the end users line.

If the line is to noisy it would be stupid for the DLM to move you onto none-interleaved until the FEC count gets to a low level of 0 - 25 per minute over a 14 day period this not going to happen on my line as it's well above that level more like 300 - 1200+ per min.

It's just my theory into why some End Users get fastpath and others never do.

http://en.wikipedia.org/wiki/Forward_error_correction

[burakkucat]

Hmm . . . An interesting theory based on your own observations. I wonder if others can supply evidence that agrees with you proposal? 

[Chrysalis]

Sadly newt your daily ES is simply too high.  It has to be extremely low to go down a profile.

Not saying FEC gets ignored, I have no idea, but I am pretty sure your ES per day is too high.

[NewtronStar]

Sadly newt your daily ES is simply too high.  It has to be extremely low to go down a profile.

Not saying FEC gets ignored, I have no idea, but I am pretty sure your ES per day is too high.

My errored seconds are 4 X lower than BaldEagle1 

[NewtronStar]

Hmm . . . An interesting theory based on your own observations. I wonder if others can supply evidence that agrees with you proposal? 

I hope so B*CAT after 3 years with FTTC and still the DS is interleaved it must be the level of noise on my line that is stopping the DLM moving it onto fastpath it's the only reason that I can see, errored seconds look fine crc's quite good and the snrm looks ok for the line sync with an undulating attainable over 24 hours.

Fastpath on the downstream is not my holy grail it's more to do with the why this line is not getting the none interleaved option 

[Ixel]

Hmm . . . An interesting theory based on your own observations. I wonder if others can supply evidence that agrees with you proposal? 

Zen's FTTC training document mentions that DLM takes FEC into account, this looks like it is true.

[NewtronStar]

Hmm . . . An interesting theory based on your own observations. I wonder if others can supply evidence that agrees with you proposal? 

Zen's FTTC training document mentions that DLM takes FEC into account, this looks like it is true.

Would love to see Zens FTTC training document  did see your thread and the download link but the format of the Doc was unusable with the software I have installed on the PC for example don't have MS office only MS Works   

[burakkucat]

Point me to the link and I'm fairly sure I could convert it into a PDF file. 

[Chrysalis]

Sadly newt your daily ES is simply too high.  It has to be extremely low to go down a profile.

Not saying FEC gets ignored, I have no idea, but I am pretty sure your ES per day is too high.

My errored seconds are 4 X lower than BaldEagle1 

the threshold to stay on fast path is not the same as the threshold to return to fast path. The latter is much lower, and I think it is 10x lower.

[kitz]

My errored seconds are 4 X lower than BaldEagle1 

Thats an unfair comparison to make.  You cant compare the number of Errored Seconds on an Interleaved line, to one that isnt Interleaved.
Theres more than one algorithm used to get an interleaved line back to non-interleaved.

BaldEagle is still below the limit for Interleaving to be applied.
Your line isnt below the limit for Interleaving to be removed.

The other algorithm is the length of time before the DLM will act on removing interleaving, and this is based on line history.  Its why after my recent bout with DLM, it only took one day of stability before it took me back down a notch again.. yet on some other lines it will take months.   It takes line history in to account to stop DLM flapping between interleaved and non -interleaved.

BE hasnt been Interleaved since the 26th of Aug.  If you look at his Err Secs before that they are much less than they are now.

[Bald_Eagle1]

My errored seconds are 4 X lower than BaldEagle1 

Mine tend to be around 8 to 9 times lower when interleaved.

[Chrysalis]

When I was last interleaved I used to get over 1500 CRC a day on fast path (cannot remember ES sorry).
When I got interleaved my daily CRC literally dropped to single figures if not 0. It was extremely low. Which obviously meant my ES was also extremely low.

If Openreach allowed a line back onto fast path which was getting say 100ES a day whilst interleaved, that line will very likely be bouncing back to interleaving after a single day.

Try checking ronski's line the day before he got returned to fast path, that may be a fair indication of what is needed.

[Chrysalis]

Newt try capping your downstream to 27000 or even 25000 that might make enough impact to get DLM to act.

[Ixel]

Just wondering if I should cap my line speed. Still stuck on 49M down, but the upstream did go up from 15M to 20M after a short time. What do you think, worth trying or should I accept 49M is the best I can get with a downstream SNRM of around 15dB to 16dB? I'm guessing this probably only works best with interleaved lines though, it probably won't help my banding prediciment.

[Chrysalis]

every time I have been synced with even 1 extra db snrm, I found a significant change in error count.  Its amazing how effective it is. Worth trying, but do not cap it too much, because it may band you lower.  The issue you have is banding not interleaving, I think if you not syncing at the same speed as the upper limit of the band then it wont be removed.