Try http://loki10.mpi-sws.mpg.de/bb/bb.php (don't select anything, just click 'start measurement')

On TalkTalk (direct) i'm getting a sync of 18.3 meg on a 29 db attenuation @ 6db noise margin...this is using a infineon modem (draytek 120). Yet using a broadcom router (billion 7800n) gives me 15.5 meg and even tweaking the noise margin on that to 3db still doesn't give me 18 meg. Since TalkTalk have just LLU'd your exchange, your exchange MSAN is almost certain to have an Infineon chipset...i'd strongly recommend you go for a Infineon chipset router for the highest sync speeds eg Netgear DGN1000, DGN3500, Dryatek 120, 2820, 2830 etc.

SNR margin at 1.9dB now, found it as low as 1.7dB before.

It seems to be falling quite a bit, is this normal behaviour?

If I were to resync should I expect a higher sync but less stability?

I'm used to the BT Wholesale setup where the noise margin would hang around 6dB and fluctuate by ~±1dB. Here it doesn't seem to have a target and will just go as low as it can before it gets unstable.

ADSL2+, using double the frequency range of ADSL Max, is more susceptible to noise, as the higher frequencies are more likely to get hit. Yes, a greater variation over 24 hours is likely. Not always the case though.

If I were to resync should I expect a higher sync but less stability?

If you resync when the margin is low, i.e. the ambient noise is high, the result is the opposite of that. Your noise margin returns to your (tweaked) value, hence stability improves, but the sync speed falls.

But are you lowering the SNR yourself? If so, i'd suggest leaving it 6db and getting an infineon router and then just enjoy using your connection

In reply to a post by RobertoS:

ADSL2+, using double the frequency range of ADSL Max, is more susceptible to noise, as the higher frequencies are more likely to get hit. Yes, a greater variation over 24 hours is likely. Not always the case though.

If I were to resync should I expect a higher sync but less stability?

If you resync when the margin is low, i.e. the ambient noise is high, the result is the opposite of that. Your noise margin returns to your (tweaked) value, hence stability improves, but the sync speed falls.

I always thought lower SNR was faster. Should have read a little closer.

So if I find the noise margin higher at say 7-8dB for example it may increase speeds slightly?

Will probably get a Vigor 120 anyway.

Read all about it .

I think you are confusing the "target" noise margin used at sync-time, which is what you are tweaking, with the behaviour of the margin thereafter. You may also be confusing noise margin with noise, but I don't really think so. The figure you see is the margin at that time you look.

Edited by RobertoS (Thu 16-Aug-12 21:59:18)

A 6dB SNRM is good for a 13143Kbps sync, interleaved, with a 37.5dB attenuation using uno partial LLU (CPW) is absolutely fine for me.

As you say baby_frogmella: "...just enjoy using your connection."

Not sure that getting an infineon router is essential though? I just use a tg585v7, although I believe the TT kit at the exchange may have been previously installed by Tiscali and uses Broadcom...

Edited by 4M2 (Thu 16-Aug-12 22:07:48)

In reply to a post by 4M2:

Not sure that getting an infineon router is essential though? I just use a tg585v7, although I believe the TT kit at the exchange may have been previously installed by Tiscali and uses Broadcom...

Matching router + exchange chipsets will almost certainly result in the best sync speed. Exchanges which TalkTalk have LLU'd in the last few years use Infineon chip in their dslam so it makes sense for the OP to use an Infineon router (not tweakable). However some exchanges such as yours (ex tiscali) use a broadcom chip which is why a broadcom router is best suited.

In reply to a post by baby_frogmella:

Matching router + exchange chipsets will almost certainly result in the best sync speed.

Fair enough