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[Kamil]

Hi guys.

I would like to find out about depths of interleaving and whether it is possible to set it at certain depth on Zen service.


Mine was on with my previous provider with pings around 46ms on BTw and 33ms on Speedtest.net.

After switch to Zen I could get the same sync (5240Kbps) and 4,5meg ip profile on 52dB line. Interleaving was turned off at this point and I was seeing many more errors on the line i.e. 3000+ crc and 2400+ es in a day as oppose to when interleaving was on (pings were down to 30ms BTw and around 24ms speedtest.net).



Now to the point. My interleaving has been switched on last night and I can sync at a higher speed --> 5280Kbps plus I see much less errors per 15minute periods which in calculation will amount to 384 CRC and 288 ES in one day if it stays like this.



So because of this I have stable connection at same speed which is good of course. But my ping has gone up.. On BTw it is now 55ms and on speedtest.net 45ms. I play games online and would like to have the ping as low as possible without decreasing the speed too much as my ip profile then would drop.

Hence the question regarding depth of interleaving. Is it possible to reduce it in stages? I think mine is at 32 at the moment guessing from dg834gt interface next to D:. Does it mean it is 32ms on top of "normal" latency? Can it be halved?



Cheers Kamil

[NewtronStar]

Hi kamil welcome to the forums, I would say your line is on the noisy side and hence why your getting so many error counts on fastpast, Now that the DLM has moved you to Interleaving the depth will be high for a few weeks (14 days) if the error count remains low the DLM should lower your Interleaving Depth automatically. 

[Kamil]

Thank you newstronstar for your response.

As you can see in my previous post error rate is connected to sync and interleaving. I can appreciate that turning interleaving on would reduce the errors and I would expect that entirely. As I said previously my last provider "had me" on interleaving and the error count was acceptable but pings were lower than the ones I am getting now.

I would like to find out whether there are different depths of interleave within BTw and how do they work. Will Zen be able to set different value on that instead 32?

Cheers, Kamil

[Kamil]

Stats if it is of any help.

Mode:         G.DMT
Channel:      Interleave
Trellis:      ON
Line Status:      No Defect
Training Status:   Showtime
      Down      Up
SNR (dB):   7.3      22.0
Attn(dB):   52.0      31.5
Pwr(dBm):   19.7      11.9
Max(Kbps):   5824      1124
Rate (Kbps):   5280      448

[burakkucat]

It might be worthwhile reconfiguring your modem/router to use ADSL2 mode and not G.Dmt mode, as is currently being used.

[roseway]

An interleaving depth of 32 isn't particularly high. I also have a downstream interleaving depth of 32, and when I ping bbc.co.uk I get an average of about 18 ms.

You can see an explanation of interleaving here: http://www.kitz.co.uk/adsl/interleaving.htm

[Kamil]

It might be worthwhile reconfiguring your modem/router to use ADSL2 mode and not G.Dmt mode, as is currently being used.

Thanks for your response. I am on adslmax and my exchange is pretty crap as this is their best available service..

An interleaving depth of 32 isn't particularly high. I also have a downstream interleaving depth of 32, and when I ping bbc.co.uk I get an average of about 18 ms.

You can see an explanation of interleaving here: http://www.kitz.co.uk/adsl/interleaving.htm

Thanks for your input. Can you have a look at the rest of stats for me please? I am not sure if it is same as yours.. My ping has gone up significantly with no changes other than mentioned before.

Mode:         G.DMT
Channel:      Interleave
Trellis:      ON
Line Status:      No Defect
Training Status:   Showtime
      Down      Up
SNR (dB):   8.3      21.0
Attn(dB):   52.0      31.5
Pwr(dBm):   19.7      12.1
Max(Kbps):   5792      1120
Rate (Kbps):   5216      448
         G.dmt framing
K:      164(0)      15
R:      16      16
S:      1      8
D:      32      4
         ADSL2 framing
MSGc:      1      1
B:      147      15
M:      1      1
T:      1      1
R:      0      0
S:      1.0000      1.0000
L:      1184      128
D:      1      1
         Counters
SF:      16637      16636
SFErr(CRCErr):   4      0
RS:      1131346      140403
RSCorr:      481      0
RSUnCorr:   64      0

HEC:      4      0
OCD:      0      0
LCD:      0      0
Total Cells:   3479690      0
Data Cells:   11124      0
Drop Cells:   0
Bit Errors:   0      0

ES:      411      0
SES:      4      0
UAS:      175      0
AS(Uptime):   283

INP:      0.00      0.00
PER:      1.75      1.75
delay:      0.25      0.25
OR:      32.00      32.00


Pings had gone up from 30 to over 50 so I lost around 20ms somewhere. Basically after being put on fast path I gained few ms but because of the errors the interleaving got turned back on and pings gone from 30-33 up to 50-55 on the same equipment. Different depth? Is it possible to change depth within BTw or is it simply a matter of on/off?

Cheers, Kamil

[roseway]

Your stats don't look bad for 52 dB attenuation. I think your best bet for low latency would be to have a higher target SNR margin with interleaving off. The higher SNR margin would give a somewhat lower speed, but also lower errors to compensate for the increase in errors resulting from turning interleaving off. Unfortunately I doubt that Zen will be able to implement that, but you could ask them.

[kitz]

On BTw it is now 55ms and on speedtest.net 45ms.

Just as an aside Id check latency yourself. 
The BTw test in particular always seems to give me a very high result which is nothing like I experience in the real world.  It often says my latency is around 30-35ms...   which is nothing like my true figure.

Code: [Select]

Pinging bbc.co.uk [212.58.246.104] with 32 bytes of data:
Reply from 212.58.246.104: bytes=32 time=14ms TTL=56
Reply from 212.58.246.104: bytes=32 time=14ms TTL=56
Reply from 212.58.246.104: bytes=32 time=14ms TTL=56
Reply from 212.58.246.104: bytes=32 time=14ms TTL=56


[Kamil]

Your stats don't look bad for 52 dB attenuation. I think your best bet for low latency would be to have a higher target SNR margin with interleaving off. The higher SNR margin would give a somewhat lower speed, but also lower errors to compensate for the increase in errors resulting from turning interleaving off. Unfortunately I doubt that Zen will be able to implement that, but you could ask them.

Agreed. This would be a solution potentially but I would rather not reduce my speed as it is not exactly mind blowing. The thing is before I had Interleaving turned off my pings were lower than they are now. Meaning interleaving was on back then, then off and now on again. Roseway is my depth 32 or is the delay at 25ms? I am not sure here and if it is possible to set different value for interleaving on adslmax trough isp?

Just as an aside Id check latency yourself. 
The BTw test in particular always seems to give me a very high result which is nothing like I experience in the real world.  It often says my latency is around 30-35ms...   which is nothing like my true figure.

My true result is nowhere near as good. I believe it was 32ms when pinging 8.8.8.8 before with interleaving on before it all started.. But I have not got ss for this. My current results are:

Pinging bbc.co.uk [212.58.246.103] with 32 bytes of data:
Reply from 212.58.246.103: bytes=32 time=48ms TTL=54
Reply from 212.58.246.103: bytes=32 time=47ms TTL=54
Reply from 212.58.246.103: bytes=32 time=47ms TTL=54
Reply from 212.58.246.103: bytes=32 time=47ms TTL=54


I guess I will have to wait until my 10 day period ends and request int to be turned off and see what happens with the error count in the evenings 

So does anyone know if isp can set different depth of int or is it automated process?

Cheers,
Kamil

[NewtronStar]

I guess I will have to wait until my 10 day period ends and request int to be turned off and see what happens with the error count in the evenings 

So does anyone know if isp can set different depth of int or is it automated process?

Cheers,
Kamil

I could be wrong here but when I was on ADSLMAX BTw there was no option to have Interleaving turned off by ISP, as my line was to noisy due to local loop length (distance from house to exchange) and I had an Down attenuation of 29.0 dB which gave me an IP profile of 7150 kbps,
now you have an attenuation of 52 dB, I can't see fastpath working very well on your long line.

[kitz]

I believe you can get it turned 'off' on adsl max, but its not a permanent off, and the dlm will kick in again it if deems necessary.   I don't think they can request difference depths though, it just the on/off/auto.

[Kamil]

I believe you can get it turned 'off' on adsl max, but its not a permanent off, and the dlm will kick in again it if deems necessary.   I don't think they can request difference depths though, it just the on/off/auto.

I believe they can turn it off on request but DLM will just put it back on when deemed necessary. What is strange is that I had it on and pings were in much lower then on the same connection then retrain of the line occurred and pings went down yet then I had flurry of errors like NewtronStar suggested ond INT got turned back on. Pings gone up from what was before 46ms at BTw and 33ms at speedtest.net to 55ms and 45ms respectively.

My last pings to bbc.co.uk were 47ms average and today I have decided to slow it down and see what happens.

Pinging bbc.co.uk [212.58.244.18] with 32 bytes of data:
Reply from 212.58.244.18: bytes=32 time=43ms TTL=53
Reply from 212.58.244.18: bytes=32 time=42ms TTL=53
Reply from 212.58.244.18: bytes=32 time=42ms TTL=53
Reply from 212.58.244.18: bytes=32 time=42ms TTL=53

Ping statistics for 212.58.244.18:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 42ms, Maximum = 43ms, Average = 42ms


I went from around 6dB SNR and previous speed to 10dB SNR still holding at decent speed. Please see my stats below. Any ideas regarding error rate? Are my RS not too high altogether?

Mode:         G.DMT
Channel:      Interleave
Trellis:      ON
Line Status:      No Defect
Training Status:   Showtime
      Down      Up
SNR (dB):   10.0      22.0
Attn(dB):   52.0      31.5
Pwr(dBm):   19.6      12.0
Max(Kbps):   5248      1124
Rate (Kbps):   4672      448
         G.dmt framing
K:      147(0)      15
R:      16      16
S:      1      8
D:      32      4
         ADSL2 framing
MSGc:      1      1
B:      165      15
M:      1      8
T:      1      1
R:      16      16
S:      1.0963      9.0000
L:      1328      128
D:      32      4
         Counters
SF:      398308      398314
SFErr(CRCErr):   44      0
RS:      27084974      3384666
RSCorr:      7427      0
RSUnCorr:   1407      0

HEC:      45      0
OCD:      4      0
LCD:      0      0
Total Cells:   74609856      0
Data Cells:   975688      0
Drop Cells:   0
Bit Errors:   0      0

ES:      18      0
SES:      0      0
UAS:      135      0
AS(Uptime):   6772

INP:      1.54      2.00
PER:      1.91      1.96
delay:      8.77      9.00
OR:      29.18      28.44

Bitswap:   0      0
Total uptime:   6911

Total time = 1 hours 59 min 18 sec
SF  = 406565
CRC = 44
LOS = 0
LOF = 0
ES  = 18
Latest 1 day time = 1 hours 59 min 18 sec
SF  = 406565
CRC = 44
LOS = 0
LOF = 0
ES  = 18
Latest 15 minutes time = 14 min 18 sec
SF  = 50445
CRC = 7
LOS = 0
LOF = 0
ES  = 3
Previous 15 minutes time = 15 min 0 sec
SF  = 52923
CRC = 20
LOS = 0
LOF = 0
ES  = 8
Previous 1 day time = 0 sec
SF  = 0
CRC = 0
LOS = 0
LOF = 0
ES  = 0
15 minutes interval [-30 min to -15 min] time = 15 min 0 sec
SF  = 52982
CRC = 0
LOS = 0
LOF = 0
ES  = 0
15 minutes interval [-45 min to -30 min] time = 15 min 0 sec
SF  = 52923
CRC = 0
LOS = 0
LOF = 0
ES  = 0
15 minutes interval [-60 min to -45 min] time = 15 min 0 sec
SF  = 52923
CRC = 0
LOS = 0
LOF = 0
ES  = 0
Showtime Drop Reason:   0
Last Retrain Reason:   0


Regards,

Kamil

[NewtronStar]

The error counts look ok, thats what Roseway was saying in his post you need to raise the SNRM on the router its a trade off higher pings for slower thoughput & less error counts it's a fine balance, If your line stats are going up and down (morning to evening) this makes it even harder for you to find the right balance.

and here you can look at my pings on 40/10 FTTC there not that impressive

#   IP Address   Response  Time   TTL
=   ==========   ===============
1   212.58.244.70   30 ms                  64
2   212.58.244.70   30 ms                  64
3   212.58.244.70   30 ms                  64
4   212.58.244.70   30 ms                  64
5   212.58.244.70   30 ms                  64

[Kamil]

Cheers for that

I have spoken to Zen and they put my setting for int to off so hopefully I will get lower pings and stable connection still. I currently sync at 3680Kbps and this aint too bad for my 52dB line. I was as high as 5800~Kbps that would not work with fast channel.

Will wait now and see how it pans out when its finally off.

Cheers

Kamil