Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: daveesh1 on July 11, 2017, 07:54:34 AM

Title: DLM
Post by: daveesh1 on July 11, 2017, 07:54:34 AM

Had DLM intervene back in may and put interleaving on the line. Then last night a couple of power cuts didn't effect me as ups kicked in but at 3.10 this morning DLM has increased the applied interleaving but I can't see why ES errors are very low could it be DLM reacting to power cuts last night even though I was not effected any ideas

Title: Re: DLM
Post by: kitz on July 11, 2017, 09:59:53 AM

Quote

this morning DLM has increased the applied interleaving

I cant see where any actual DLM changes have been made.   Your DLM profile is still INP=3.   Interleave delay = 8ms

If you mean Interleave depth, although the value has changed, it wont make any difference to your performance.   Using INP=3, the modem calculates the sufficient error protection required to be able to recover from noise burst of 3 DMT symbols.   DMT symbols (bits carried in the bin) can vary depending on your sync speed - the higher the sync speed then the more DMT symbols.

Your sync speed has increased from 39192 -> 43845.  Thus depth has increased 767 -> 859.    If you look on MDWS, there is a direct correlation between your increased sync speed and interleave depth.  :)

More info Interleaving (http://www.kitz.co.uk/adsl/interleaving.htm#interleave_depth) and Impulse Noise Protection (INP) (http://www.kitz.co.uk/adsl/interleaving.htm#INP)

Title: Re: DLM
Post by: daveesh1 on July 11, 2017, 10:23:55 AM

Thanks Kitz did notice the sync speed had increased slightly. Could this be the start of DLM looking to reduce interleaving depth

Title: Re: DLM
Post by: kitz on July 11, 2017, 10:48:07 AM

I havent looked in detail, but I notice your current SNRm is 6.1dB... previously it was ~8dB which would likely account for the better speed now.   
Ive no idea why the SNR jumped to 8dB on 22nd of June..  sorry :/