Stability options and enhanced traffic weighting

[#1]

Quote from: Jameseh

My other trialists have been pretty quiet, so your reporting so far has been invaluable.

cant be talking about me there james. i brought this fixed speed up months ago an asked over an over again for PN to check with BTw if it was part of the design of the new DLM or a BUG an unfortently no staff took the task up.
so i was pleased to find the op on the other thread had manged to get the info at last
mine on standard stability and fastpath on both times i found my self on fixed sysnc it sorted its self after a week or 2

[#2]

No, I'd never refer to you as being quiet

[#3]

James,
Any chance you could check what happened last night?   
I rebooted the router this morning at 08:23 (BST times in this post) when I saw lots of 'LCP allowed to come up', but only one 'CHAP authentication success' overnight - unfortunately I forgot to save the log file before I did it 
Anyway I can see from the NTP pool monitoring that the link was down from just after midnight to just before 5AM.
I'd stopped playing with the router remotely at about 22:00, so I don't think it was related to anything I did...
Router came back up the same as last reported:
ADSL Link                  Downstream      Upstream
Connection Speed    2964 kbps            447 kbps
Line Attenuation        43.0 db                23.0 db
Noise Margin              22.0 db                22.9 db
Thanks

[#4]

Okay, over the last couple of days I can see:
08:35 22/Jun/2009 ->  21:31 24/Jun/2009
21:31 24/Jun/2009 ->  00:03 25/Jun/2009
05:01 25/Jun/2009 ->  08:22 25/Jun/2009
Latest connection starting at 08:23 25/Jun/2009.
I'm afraid that I'm not aware of anything that would have impacted your connection last night.

[#5]

Thanks James - well, those times tie up exactly with what I saw, even if it doesn't shed any light on why it happened.
Just 'one of those things', I guess...

[#6]

Well, there was a DLM upward adjustment on Saturday at 08:26 BST:
before:
27.06.2009 07:16:00 - Bit rate DN 2964 kbit/s, Bit rate UP: 447 kbit/s, SNRM: 21.8 dB
after:
27.06.2009 07:46:00 - Bit rate DN: 3511 kbit/s, Bit rate UP: 447 kbit/s, SNRM: 21.8 dB
so that was starting to look promising, but...
...then, yesterday ,something happened again, but I'm not exactly sure what:
1. the last record I had from the DG834 was: 28.06.2009 07:26:09 - Bit rate DN: 3511 kbit/s, Bitrate UP: 447 kbit/s, SNRM: 21.3 dB
2. It looks as though the link went down sometime between 08:29  and 08:41 BST, and remained down all day - looks like router was 'negotiating' continuously.
3. Tried forcing a retrain, then did a reboot, and finally a setup from factory default, all with the same result.
4. Connected SAR715PVW came up OK in ADSL (g.dmt) mode as expected (it doesn't do the ADSL2 modes). Left it like that last night.
5. This morning tried DG834 again with only g.dmt enabled, came up fine.
6. Tried with just ADSL + ADSL2 + ADSL2+ modes enabled, no joy
7. Tried ADSL + ADSL2, still no joy
8 Tried again with just g.dmt enabled, and connected OK - which is how I have left it for now.
So, from the time, it looks as though the problem was initiated by the DLM or something else at the exchange?
Can't be 100% sure, I suppose - so I would be interested in any thoughts about what might have happened.
I probably ought to try another ADSL2+ capable router, but I'm not sure when I'll be able to do that.

[#7]

Morning,
Just to really confirm what you've been seeing, there was no connectivity from 08:47 to 17:57, where there was a one minute connection and then picked up again properly from 18:04.
There's been a few connections since, presumably instigated by the change in router and I'm now seeing you as being logged in for a little over 3 hours now.
If you'd like me to send you out a loan TG585v7, I'd be happy to do so.  If you'd like, we can add you to the Easy Setup trial and get a router sent out from the office?

[#8]

James,
Thanks for the offer, however I should be able to find another router - I just gave back my son's Voyager 210 a couple of days ago and I have another one kicking around somewhere - it is more a case of when I'm at home long enough to be able to play around and not leave the system down for everyone else...
I did try again briefly this morning but the DG834 still wouldn't sync if either ADSL2 or ADSL2+ were enabled.
I mentioned that I had tried setting the DG834 back to factory default - actually I left the SNR slider at it's default 100%, so here are the current stats - still pretty stable 

2009-06-30 08:03:08
Upstream rate = 448 Kbps, Downstream rate = 3072 Kbps
Mode:                   G.DMT
Channel:                Interleave
Trellis:                ON
                Down            Up
SNR (dB):       26.0            27.0
Attn(dB):       40.0            25.0
Pwr(dBm):       19.3            11.6
Max(Kbps):      8128            1268
Rate (Kbps):    3072            448

[#9]

Yep - It certainly looks pretty stable!
Or dare I say, super stable?

[#10]

OK - I managed to have a quick poke last night between about 8 and 10 PM.
Other router:

Connection Status	 	Connected
Us Rate (Kbps)	 	448
Ds Rate (Kbps)	 	3067
US Margin	 	23
DS Margin	 	15
Trained Modulation	 	ADSL2Plus
DS Line Attenuation	 	38
US Line Attenuation	 	24
Path Mode	 	Interleaved

and back on DG834:

Mode:			G.DMT
Channel:		Interleave
Trellis:		ON
Line Status:		No Defect
Training Status:	Showtime
		Down		Up
SNR (dB):	25.1		26.0
Attn(dB):	40.0		25.0
Pwr(dBm):	19.2		12.1
Max(Kbps):	8000		1240
Rate (Kbps):	3072		448

Not sure exactly what the other router is - it's a ISINE modem + 4-port switch + wireless AP job - probably AR7WRD based.

[#11]

The noise margin is considerably higher on the Netgear.
Possibly indicates a fault with the router?  Especially couple with the increase in downstream attenuation when using the Netgear.

[#12]

The Netgear is running in G.DMT  mode and not ADSL2+ so the attenuation figures will be different as the higher frequencies are not being used. Having said that the attenuation should be less not more. Not familar with the Netgear so don't know how to change it to ADSL2+ or Auto so hopefully someone else will help with this.
Also why is the upstream at 448kbps?

[#13]

Quote from: itsme

The Netgear is running in G.DMT  mode and not ADSL2+ so the attenuation figures will be different as the higher frequencies are not being used. Having said that the attenuation should be less not more. Not familar with the Netgear so don't know how to change it to ADSL2+ or Auto so hopefully someone else will help with this.

I have a netgear DG834GT and to enable ADSL2+ you need to go to Advance ADSL Settings and then ensure that all of the modulation types are set. Or if you are trying to force a specific modulation deselect all of them except the one you are hoping for the router to sync with, the below should be options to select from
MultiMode
G.DMT
G.Lite
T1.413
ADSL2 (G.992.3)
ADSL2+ (G.992.5)
Reach Ext. ADSL (Annex L)
Double Upstream (Annex M)

[#14]

if your to far from the exchange for adsl2+ to make any diffrence the dlam will force an adsl2 sync no matter what you tell your router to use. if your on the edge of adsl2 and + i guess trying to force adsl2+ would have an effect on the dlam

[#15]

The short summary of the history (most of it given earlier in this thread):
- DG834 was operating happily on ADSL2+ since I first installed it at the end of April, just  after being put on the trial.
- Continued operating after starting the 'super stable' option from 16th June to 27th June, including various changes to framing parameters and sync rate initiated by DLM around 08:30 in the morning on various days.
- One unexplained outage early on 25th June.
- On 27th the router lost sync at around the time DLM typically makes changes and did not recover until router was manually changed from multimode to G.DMT.
Certainly the SNR looks a bit odd, having been about 21 - 22 dB at last two syncs of 2964 and 3511 kb/s (ADSL2+) and now 25 dB at 3072 kb/s (G.DMT) with Netgear, whereas the other router shows 15 dB at 3067 kb/s (ADSL2+).  Since I've never used the other router before, I need to be somewhat careful reading too much into it, other than it manages to negotiate ADSL2+.  Maybe I'll borrow that Voyager 210 again...
I guess I'd also better try the more recent Netgear firmware 12 -> 14, but I rather doubt that will change anything.
Otherwise, it looks like either it objects to a particular set of ADSL parameters or it is infant mortality