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[setecio]

I wonder if anyone can help me understand the process in this :

BT Broadband was ordered for a house and activated, a Netgear DG834PN was plugged in a week later and used for 30 minutes, it showed a sync rate of 2Mb. The DG834PN was then turned off for a week and when it was turned on it was syncing at 8Mb.

I understand there is a 10 day initial training period and am just trying to understand how it works and the effect or non effect of a connected modem or no modem at all. I thought it would require a syncing modem and would slowly adjust upwards to the max.

Does it start at activation or does it start at the first time a modem is connected ?

How did the sync speed jump up to full speed without a modem being on. Did it see it's first connection at 2Mb work fine and then try 8 for the next sync (which was a week later).

If no modem was plugged in during the first 10 days would it have settled at 8Mb or would it have waited until the first modem was connected and trie at 2Mb.

There is no problem here, I'm just trying to understand the initial training process.

Thanks.

[roseway]

The so-called 'training period' is mainly about setting a benchmark connection speed (Maximum Stable Rate, MSR) against which any future complaints about speed will be measured. The router will negotiate the best speed it can with the DSLAM right from the start; there's no 'adjusting upwards' taking place over the training period.

The fact that the router connected initially at only 2 Mbps suggests that it had maybe been configured as a fixed-speed service initially, but when it was connected the second time it had been correctly configured as a Max service.

[setecio]

OK thanks, so it won't matter if broadband is activated for a month before the modem is setup and switched on .... the training period kicks off when a modem is first detected and should go for max speed straight away.

[roseway]

That's right.

[roseway]

I've moved Ezzer's excellent comment here. and made it a sticky.

[rjpearce]

I've got a related question...

I've had my dsl max connected for the last 6days. I've been tinkering with a variety of things to improve the sync speed..

1) I removed all the in house wiring from the master socket (didnt need it anyway!) sync jumped from 3.5mb to 6.0mb  .
2) Ordered interleaving off.. Got me up to 7.0mb 6db margin 
3) Spent an hour or 2 testing the various filters i had selected the best one and the sync jumped to 8.0mb - 6.5db margin 
4) I Went online and bought a proper NTE5 faceplate with asdsl filter built in - This is where it went a bit tits up..    My margin has improved loads but my sync has fallen. I was first synced at 7.6mb (9.5db margin) since rebooting my router a few times the sync has got lower and lower.. but the margin is going up!... I'm now only sync'ed at 7.1mb with an (10.5db margin).. Is the DLM seeing my re-sync's (when i reboot the modem) as the line dropping? and then lowering my next sync?.. in an effort to make it more stable?

Does anyone have any ideas why this is happening? I've raised a support ticket with my ISP (newnet) to confirm that I am on a 6db profile. Apart from that I am not sure what to try.

My router is a Billion 7402R2 with an  Argon 432 chipset.
I have been using the Coding Gain option on the router to help raise the Sync. It's currently set to 7 (the highest setting).
If i leave to auto the sync goes down to 6mb with ridiculous amounts of SNR margin.

I'm currently also using an NTE5 faceplate from ADSL Nation (XTE-2005).

Line Stats:

Connected    true
Operational Mode    G.Dmt
Annex Type    ADSL2A
Upstream    448000
Downstream    7104000
CO Vendor    BCLA

----------------------Downstream    Upstream
SNR Margin          10.5 dB        21 dB
Line Attenuation  40.0 dB         22.0 dB
CRC Errors           45               0
Latency             Fast        Fast

Big thanks to anyone who can help

-Rich

 

[roseway]

Hi and welcome

It rather looks as though your target noise margin has been raised to deal with a line which seems to be unstable (maybe as a result of frequent re-syncs caused by your own work). Switching off interleaving may not have been a good idea until you had time to see how the connection performs, and I doubt if that was the reason for your increase in connection speed - interleaving sometimes limits the highest connection speed to 7 Mbps-odd but it shouldn't bring 7 down to 6.

To be honest, I think you're doing rather well for an attenuation of 40 dB, and maybe your connection has found it's optimum point. The practical difference between 7 Mbps and 8 Mbps is really rather insignificant, and any more tweaking may just make your connection unstable. I would leave it as it is for a bit and see how it goes before pushing harder for a reduction in the target noise margin.

[rjpearce]

Hi,

Thanks for your input ...

I think when interleaving was turned off i was put onto a 6.5db profile. With interleaving on the profile was around 10db.
Which is why i think i gained a few of mb when it was turned off.

Apart from the loss of speed the line is rock solid, the SNR Margin only deviates by 1db each day/night. I'm only 1.5km from the exchange (as the crow flies) but it must go a very long way round for 40db attenuation.

I will leave it a few weeks with no tinkering to see if the rate will go back up, I know there is very little difference between 7mb and 8mb.. But i just want to get the best i can  It's definately worth mentioning that the main killer of my original connection speed was definately the in-house wiring.

Thanks again

-Rich

[rjpearce]

Just spoke to my ISP the MSR/FTR can be re-trained just by turning off the router for 40mins..
(Might be worth adding this to your sticky on the 10 day stabilisation period..)

Newnet support said:

"You can Start a recalculation of the MSR/FTR yourself.
Simply power off the router for around 40 minutes and then power back on.
Leave the router connected and you should start to see the line rate increase."

 

-Rich

[roseway]

I'm afraid that's not true at all. Goodness knows where they got that idea from.

[rjpearce]

Hi, You were right.. It made no difference at all. What a load of    . Oh well thanks again for the advice

-Rich

[kitz]

"You can Start a recalculation of the MSR/FTR yourself.
Simply power off the router for around 40 minutes and then power back on.
Leave the router connected and you should start to see the line rate increase."

Ooops indeed 

Seems like someone perhaps got muxed up with the IPprofile...   which continually changes over the time you are on maxdsl :/