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[AngryMonkey]

Hi,
BT Infinity 2 was installed on the 9th and since then the stats have looked like this:

Date	| Actual Rate	| Attainable Rate	| PathMode	| Interleave Depth	| Average Ping to Google
14/08	| 58165	| 66781	| FastPath	| 1	| 10
15/08	| 34765	| 49116	| Interleaved	| 503	| 18
16/08	| 36389	| 48412	| Interleaved	| 2685	| 23
17/08	| 37410	| 47332	| Interleaved	| 2761	| 28

It appears the line started at a high rate with fastpath (which was rock stable as well), but then for some reason the line was knocked way down and interleaved. Since then it looks like the exchange is trying to get the rate up, but at the expense of increased interleave depth and higher pings.

My main use is VOIP and online gaming so whilst I appreciate the exchange is trying to help me get a higher rate, i'd actally prefer to sacrifice some rate in exchange for a lower ping. I have an Asus DSL-ac68u with g.inp enabled, maybe I could switch to a Billion modem and manually cap the sync rate?



Thanks
AM.

P.S
As an aside, in order to contibute something back to the community, here is a VB script I wrote to extract the line stats from the Asus dsl-ac68u every 5 minutes and dump to a CSV file. I use excel to look at the data and have a bunch of graphs that show snr vs line speed and other stuff. Feel free to use/modify if any of any use.

http://www.filedropper.com/getasusstatstext

[Dray]

Are you using the ASUS as a modem?

[mlmclaren]

Date	| Actual Rate	| Attainable Rate	| PathMode	| Interleave Depth	| Average Ping to Google
14/08	| 58165	| 66781	| FastPath	| 1	| 10
15/08	| 34765	| 49116	| Interleaved	| 503	| 18
16/08	| 36389	| 48412	| Interleaved	| 2685	| 23
17/08	| 37410	| 47332	| Interleaved	| 2761	| 28

It looks wrong from the start, I would expect their to be such a gap between the actual sync rate and max sync rate when on fast path, and the continued drop would seem alarm me, I do believe you need to contact BT and log a fault.

However it would be interesting to see what your estimates speeds for your address or telephone number are, you can find them here:  https://www.btwholesale.com/includes/adsl/adsl.htm?s_cid=ws_furls_adslchecker

[WWWombat]

It appears the line started at a high rate with fastpath (which was rock stable as well), but then for some reason the line was knocked way down and interleaved.

That's kinda self-contradictory. DLM will have put you onto an interleaved profile precisely because it thought the line wasn't "rock stable". It likely saw a high rate of errors, though, rather than a high rate of resyncs: the error rate is the thing that drives DLM more.

The increase in latency by 8ms is a standard first step that comes from this intervention, and explains your day 2 ping times. Your actual and attainable rates are a bit out-of-the-norm though (actual speed would normally drop by 6-8Mbps, while attainable would increase by a similar amount).

On days 3 and 4, DLM is likely to have intervened again. It probably isn't "trying to get the rate up", but is more likely to be still trying to get the error rate down. The continuing increases in latency suggest that to be the case.

Do you have access to the error statistics?

On the whole, I don't trust the ASUS routers to act as VDSL2 modems. There just seem to be so many problems and incompatibilities that I'd never recommend anyone bothering. Unfortunately, it means I don't bother to remember all the individual foibles of different models - so someone else might have to help you there.

It looks wrong from the start, I would expect their to be such a gap between the actual sync rate and max sync rate when on fast path, and the continued drop would seem alarm me,

The variation there suggests the noise on the line (not necessarily audible noise) varies over time quite considerably, so monitoring the SNRM value closely would be valuable.

[AngryMonkey]

Hey,
Thanks for your replies all, some good information.

WWWWombat - "It probably isn't "trying to get the rate up", but is more likely to be still trying to get the error rate down."

That actually makes a tonne of sense. I guess the download rate going up wasnt the goal, its just a happy by-product of increasing the interleave in an attempt to reduce errors.

Rather than spend hours trying to check if this is right or not, ive taken a different approach and ordered a totally new line (including line to the pole) with a new BT Infinity contract which i'll put a different modem on (maybe a Billion instead of an Asus as they seem to be mentioned a lot). I'll see if theres any big difference between the two broadband lines, then bond them

[AngryMonkey]

The variation there suggests the noise on the line (not necessarily audible noise) varies over time quite considerably, so monitoring the SNRM value closely would be valuable.

I think you're right - below is a graph of my SNR Margin (also showing actual and attainable data rate). Is bounces between 4 and 6 all day, would you say this is a considerable change, or to be expected at 3km from the exchange 1.2km from the cabinet?

[NEXUS2345]

With FTTC, distance to the exchange is not really the metric used. Distance to the cabinet is the usual metric used, as past the cabinet it is fibre and so distance between cabinet and exchange makes very little difference.

[AngryMonkey]

With FTTC, distance to the exchange is not really the metric used. Distance to the cabinet is the usual metric used, as past the cabinet it is fibre and so distance between cabinet and exchange makes very little difference.

Very interesting, your right, I'm 3km from the exchange but only 1.2km from the cabinet. Still not close, but not as bad as I thought.

[Black Sheep]

You're nearer than that to the FTTC Cab with those download connection rates ............... unless you're being fed by shower cable ?? 

[j0hn]

I found that the Asus massively exaggerated my max attainable compared to every other modem I've tried. The huge swings in SNRM don't surprise me at all as the Asus really struggles to maintain a 6dB margin, especially on longer lines like yours.

I wouldn't log a fault from any statistics you've taken from the Asus. I'd recommend trying another modem 1st as the modem may well be the problem. The continuously increasing interleaving is probably due to high levels of Error Seconds. You'll never know for sure though as there is absolutely no way to obtain these from the modem. The only way to obtain ES/SES numbers is to enable 24 hour line diagnostics which records the info direct from the DSLAM on to a USB connected to the modem.

In short, ditch the Asus and try another modem. You mentioned maybe trying a Billion modem, that wouldn't be a bad choice. I'd also recommend 1 on the ZyXEL modems as an alternative.

[ejs]

I think Ixel managed to extract some ES and other counters a while ago (although I'm not sure how they got to the tc console). The DSLAM wouldn't know the downstream ES count without obtaining it from the modem.

But yes, I'd also suggest trying a different modem.

[AngryMonkey]

I'd also recommend 1 on the ZyXEL modems as an alternative.

Thanks John, do the ZyXEL modems give very detailed stats? I currently use a script to extract the following from the Asus into excel which is very useful, so a modem that gives me even more stats would be good (i love spreadsheets...)

xDSLmode=VDSL
outDiscards=4516
inDiscards=5822
outBytes=1636247783
inBytes=1652492428
outPkts=8575424
inPkts=17574261
CurrentProfiles=17a
UPBOKLE=19.9
TRELLISds=1
TRELLISus=1
ACTSNRMODEds=1
ACTSNRMODEus=1
ACTUALCE=640
SNRMpbds=5.0,5.1,N/A,N/A,N/A
SNRMpbus=5.7,5.8,5.8,N/A,N/A
LATNDown=17.7,52.9,82.8,N/A,N/A
LATNUp=4.0,39.9,60.3,N/A,N/A
SATNDown=33.3,53.3,N/A,N/A,N/A
SATNUp=4.0,40.1,60.9,N/A,N/A
fwVer= FwVer:5.5.2.3_A_A60901 HwVer:T14.F7_0.2

lineState=up
Opmode=ITU G.993.2(VDSL2)
SNRMarginDown=5.3 dB
AttenDown=17.7 dB
SNRMarginUp=5.8 dB
AttenUp=4.0 dB
DataRateDown=36389 kbps
PathModeDown=Interleaved
DataRateUp=9699 kbps
PathModeUp=FastPath
WanListMode=1
FECDown=16715425
FECUp=234
CRCDown=1003
CRCUp=56
HECDown=0
HECUp=0
ADSLUpTime=1 day, 12:47, 7 secs
ADSLActiveTime=0 min, 16 secs
PowerDown=11.5 dbm
PowerUp=5.7 dbm
ATURID=26005443434e0000
ATUCID=b5004244434da48c
FarEndVendorID=Broadcom
AttainUp=9699 kbps
AttainDown=46712 kbps
ShowtimeStart=16
TotalStart=31
ATURANSIRev=0
ATUCANSIRev=0
ATURANSIStd=0
ATUCANSIStd=0
TCM=On
InterleaveDepthDown=2685
InterleaveDepthUp=1
INPDown=1.1 symbols
INPUp=2.3 symbols
AdslStandard=VDSL2
AdslType=ANNEX_A
mtenStandard=G.dmt.bisplus (Annex L)

[j0hn]

Thats what Asus support told me when I asked them to include the ES info in the telnet stats. They said it's not possible as the modem doesn't record it. When I pointed him to Ixel using TC CONSOLE on overclockers they replied that it comes from the DSLAM. So it's even more nonsense from Asus support, and there's no reason they couldn't add those stats to the telnet output.

I tried to get a hold of TC CONSOLE a while back to see how the Asus actually performs with regards to ES on my line but looked like he hadn't been on here for some time. It also had some other "advantages" I wanted to test at the time but not so sure I would try them now.

Thanks John, do the ZyXEL modems give very detailed stats?

yes, everything any other broadcom chipset should give. They are also compatible with the stats harvesting applications, and MDWS.