7800DXL/DX/VDOX SNR Tweak Table

[BadMelonFarmer]

thanks, will email them now.

Edit:-

they have requested BT reset the profiles, but regarding disabling the profiles...

"We have requested BT reset the profiles for you. The services remains dynamic so their profiling systems cannot be disabled."

So I am not going to tweak the SNR and leave it to see what happens.

Edit:-

Already done (man, I love being on a decent ISP... the service is GREAT)

SNR back to 6.1 and my sync speed is back up to 5664. .... with ADSL max I am as happy as I am going to be with 5664.... lets hope it stays at this speed.

[peterb99]

Attached is table with new SNR values for our 7800DXL/DX/VDOX (thanks to our fourms users that helped to confirm the values)

If more values are needed, let me know and I can add them to the table.

Some values may need to confirmed depending on default SNR values.

Just got my 7800DXL yesterday and am already getting better subjective speeds than with Linksys wag354g it replaced.

I am confused by the table though. My router has version 2.31.RC4.3 of the firmware, which I believe is the latest. On the 'Configuration' --> 'SNR' page the text says:

"This field can be adjusted to affect the SNR value so as to achieve the highest possible sync speed.
Note that a value set too low may affect stability, a balance needs to be achieved between speed and stability.
There are no set values recommended as each ADSL line will be different.
A value of 6 is a good starting point, this is the target SNR, from here you can gradually reduce values to achieve the highest possible sync speed whilst still maintaining stability. e.g 5,4...
1 is the lowest possible value."

This seems to be counter to the table in the original posting. I'm interpreting a value of '6' as meaning a SNR of 6db. (Next to the field where you enter the value is the text ' dB [ Auto : -1 ]'. Has the firmware changed since the original posting?

I set the value to '6' yesterday but on the 'Status' --> 'Statistics' 'xDSL' screen the downstream SNR margin is reported as 8.4 currently. Yesterday it said '9.1'. I understand some variation is to be expected (but it's not at '6', which is surely where it should be!).

I guess that's 2 questions.

Either way, fabulous router and I'm already loving it!

Thanks!

Pete

[swatboy79]

Read this thread...

viewtopic.php?f=18&t=807

That's how it works.

[peterb99]

Read this thread...

viewtopic.php?f=18&t=807

That's how it works.

So the descriptive text on the latest firmware Billion SNR management screen is wrong? Because it plainly implies set 6 to get 6db.

You may need to be patient with me. I'm pretty good at reading, not so good on the techie part of SNR management.

[billion_fan]

Read this thread...

viewtopic.php?f=18&t=807

That's how it works.

So the descriptive text on the latest firmware Billion SNR management screen is wrong? Because it plainly implies set 6 to get 6db.

You may need to be patient with me. I'm pretty good at reading, not so good on the techie part of SNR management.

The design is based on the stanard SNR settings from BT, normally the base rate is 6db.

If you need to tweak further, you need to follow the table I posted at the start of this thread, so for example you have 8db and want to acheive a SNR of 3db, then you enter 1 in the SNR tweak page. (which is -5db off 8db = 3db)

[peterb99]

The design is based on the stanard SNR settings from BT, normally the base rate is 6db.

If you need to tweak further, you need to follow the table I posted at the start of this thread, so for example you have 8db and want to acheive a SNR of 3db, then you enter 1 in the SNR tweak page. (which is -5db off 8db = 3db)

Thank you. I tried using the values from your table to get the snr down from 9 to 6 and it worked as you said! I'm sorry I doubted you - the text on the Billion management page seems plain misleading.

According to Demon their 'internet servers' will manage the connection so my last question is whether what I see now as a result of changing the value in the Billion management screen will cause the achieved rate to persist or whether the 'internet servers' will keep fighting any changes I make.

Many thanks again for your settings and patience!

Pete

[billion_fan]

The design is based on the stanard SNR settings from BT, normally the base rate is 6db.

If you need to tweak further, you need to follow the table I posted at the start of this thread, so for example you have 8db and want to acheive a SNR of 3db, then you enter 1 in the SNR tweak page. (which is -5db off 8db = 3db)

Thank you. I tried using the values from your table to get the snr down from 9 to 6 and it worked as you said! I'm sorry I doubted you - the text on the Billion management page seems plain misleading.

According to Demon their 'internet servers' will manage the connection so my last question is whether what I see now as a result of changing the value in the Billion management screen will cause the achieved rate to persist or whether the 'internet servers' will keep fighting any changes I make.

Many thanks again for your settings and patience!

Pete

It all depends, if there are many drops in the connection, the BT Profile will kick and override your SNR tweaks set on the Billion.

If the line seems stable then there should be no need for your ISP to override the SNR tweak set on the Billion.

[Philip_L]

Hi

If you wish to set the same SNR override value as you had previously on another router using the Broadcom chipset (say 7800N), then all you need to do is:

Take the figure used on previous router / 16

For example, a figure of 50 for SNR override used on the 7800N would need to be entered on the new 7800 series as 50 /16 = 3.125

The reason for this is the interface is taking any figured entered and multiplying by 16, presumably because this allows for figures to be entered looking more like db values.

Regards

Phil

[thubleau]

The setting table works
I went to 4091 and established a rock solid connection on a bad line with a snr of 4.4
4088 would not connect because it equalled a snr of -3.6db
4090 gave nearly the same as 4091 but was flaky and drop outs occurred

[Tooros]

Could some help me out a little with this SNR tweak?
The table on page 1 here seems to make sense to me (in terms of what number = what value, rather than pure logic)

What I'm confused about is what am I aiming for?

I'm on BE.
I'm guessing they set 3,6 or 9.

Do I have to call them to ask what I'm set for?
Can I see it in the status on the router itself?

Assuming I discover what value I'm supposed to be at - what adjustment am I then aiming for? To get as close to what the ISP thinks I'm on or lower? That's the bit I'm a little fuzzy on.

Hope someone can help - Cheers.