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[111888]

what does a interleave of 8 on downstream mean?

It says im on fast path on both upstream and down stream. Is lower interleave depth better?

[Edinburgh_lad]

https://kitz.co.uk/adsl/interleaving.htm

[Alex Atkin UK]

https://kitz.co.uk/adsl/interleaving.htm

In this case however if its fast path and interleaved, that suggests to me its using G.INP so the stuff on that page doesn't really apply as its different to normal INP and doesn't add latency.

[underzone]

There is not a lot that you can do to influence or change these settings, so best to either be happy with the modem/router you have - or start to try/swap a few different recommended models.
Once you start swapping though... you may never stop 

[111888]

It shows im on something called trellis, and for some reason bit swap has been turned off. I can't seem to enable bit swap.

[g3uiss]

What’s actually the problem with your line ?

[111888]

What’s actually the problem with your line ?

lagg during fps games.  Bitswap should be on all vdsl products.. but its turned off.

[Alex Atkin UK]

lagg during fps games.  Bitswap should be on all vdsl products.. but its turned off.

Bitswap being off is more a stability issue with the SNRm falling over time as the line quality degrades so you have less safety margin to hold onto sync if line quality degrades.  If the SNRm doesn't fall, then it probably isn't an issue even if not ideal.

What router/modem is being used as I think the last I heard of bitswap being stuck off as a modem/firmware bug.

There is some discussion of bitswapping at https://forum.kitz.co.uk/index.php/topic,21448.msg424699.html#msg424699

[111888]

draytek.It shows that Bitswap is off. and something called Trellis is on.

[kitz]

In this case however if its fast path and interleaved, that suggests to me its using G.INP so the stuff on that page doesn't really apply as its different to normal INP and doesn't add latency.

Fast path and interleaved isn't a G.INP thing.  ADSL2+ and VDSL can make use of the interleaved channel in this way regardless of g.inp.
It's also possible to see interleave depths of 4,8 on adsl.  In theory ADSL has an interleave depth of up to 64 - not that OR or BTw use that high a setting. It's even higher on VDSL depending upon which profile is in use eg 3072 for profile 17a.


VDSL and ADSL2+ often makes use of the interleaved channel to transmit non interleaved data.  This leaves the FAST channel for time critical applications such as IPTV, VoIP.  Using Interleaved Depth of 1 effectively turns the Interleaved channel into FAST mode.  Interleave is a separate process to G.INP in that either or both can be on/off.

All Openreach VDSL lines use the interleaved channel to transmit non-time critical data, the FAST channel being reserved for IPTV such as BTinternet 

Its the level of INP that is usually the clue when it comes to G.INP being enabled.   
ADSL2+/VDSL use the INP value to calculate the error protection params based on the line rate. 

Openreach retransmission (G.INP) usually has higher INP values somewhere in the 30s'/40s. 
It's these higher levels that caused a lot of the problems with Openreach g.inp Mk1 where non g.inp lines were getting INP values of 30+ causing enormous levels of error protection and thus such low sync speeds. It was the high INP value of >30  how I first identified which lines had g.inp when I was responsible for reporting problematic lines with g.inp to Openreach back in 2015 when G.INP Mk1 was first introduced.


For example on my line, currently

Code: [Select]

Interleave depth:        1 1
INP:                    46.00 0
G.INP:                  Enabled Not enabled

Interpretation
Data being sent over the interleaved channel depth of 1, so interleaving is in effect off.
INP = 46 meaning high level of INP protection = BTOR retransmission high.

======================

You also have to be careful when someone says they have Interleave 8, as they could either be meaning the depth or the delay. 
In this particular case the OP has clarified in the topic title that it is interleave depth.

[kitz]

It shows im on something called trellis, and for some reason bit swap has been turned off. I can't seem to enable bit swap.

Trellis modulation is an inner code for error correction.  It's unrelated to interleaving and it should be kept on for the vast majority of lines.

What router/modem is being used as I think the last I heard of bitswap being stuck off as a modem/firmware bug.

Yes, there are some modems that seem to have this bug in the f/w.
As you correctly say, it could cause the line to drop sooner when the SNR falls because the modem can't use any spare SNR that may be available in other tones.

What is Bit swapping.

[Edinburgh_lad]

Telnet into Draytek and run the following command: vdsl status more

Then post the findings here.

During my years of using Drayteks, I found that the status of settings is not accurately reported in the GUI. However, I don't think you can switch bitswap on from within the CLI.

The other thing to consider 'virtual noise' as a mitigating factor, which I believe has a more positive effect on the line and SNR fluctuations long term, but not sure of its effect on lag. (I may be wrong though.)

Also, I'd check with another modem, as, as I said above, sometimes settings are not correctly reported in Draytek's GUI. Have you done that to see if bitswap is indeed on/off?

If you're changing any settings on Draytek, remember to save 'config', as any restart will revert back to the original settings.

If you're bothered by lag, you could try different firmware codes for Draytek - have you tried that? I found that during my experimenting with different codes that lag/ping improved as I used different modem codes.

PS Personally, I found that more recent Drayteks are pretty bad on noisy lines with other (Infineon-based) modems handling such connections better. I found no difference in performance between Infineon- and Broadcom-based chipsets, but I did find that using a good filter (for example ADSLNation on VDSL) improves the connection speed, quality etc.

 

[111888]

Telnet into Draytek and run the following command: vdsl status more

Then post the findings here.

During my years of using Drayteks, I found that the status of settings is not accurately reported in the GUI. However, I don't think you can switch bitswap on from within the CLI.

The other thing to consider 'virtual noise' as a mitigating factor, which I believe has a more positive effect on the line and SNR fluctuations long term, but not sure of its effect on lag. (I may be wrong though.)

Also, I'd check with another modem, as, as I said above, sometimes settings are not correctly reported in Draytek's GUI. Have you done that to see if bitswap is indeed on/off?

If you're changing any settings on Draytek, remember to save 'config', as any restart will revert back to the original settings.

If you're bothered by lag, you could try different firmware codes for Draytek - have you tried that? I found that during my experimenting with different codes that lag/ping improved as I used different modem codes.

PS Personally, I found that more recent Drayteks are pretty bad on noisy lines with other (Infineon-based) modems handling such connections better. I found no difference in performance between Infineon- and Broadcom-based chipsets, but I did find that using a good filter (for example ADSLNation on VDSL) improves the connection speed, quality etc.

You sure the  XF-1e  adsl nation filter works with vdsl connections?

[Edinburgh_lad]

Very much so, and why wouldn't it? Just because it has 'ADSL' on the packaging?

Some on here will say something about ADSLNation being for ADSL etc. and frequencies, but no-one has really provided any hard evidence to support that ADSLNation filter doesn't work with VDSL.

Honestly, I tested lots when I had problems with the noise on my line (I still do, but not as much after the OR have finally done something about it) and got the best results with ADSLNation. But, it's really a personal preference and if your OR's filter works better then that's what you probably should consider using.

[Alex Atkin UK]

DSL filters are to block the frequencies used for voice, so what frequencies you use outside of those they have zero impact on.  If you don't use voice on the line, you don't need a filter at all.

There's a slight exception to this where some filters try to block other interference on the line, but unless your line is suffering this particular problem those will do nothing.