SNR

[kenny70]

Hi
just got my 7800dxl about an hour ago set it up fine and pretty pleased with it apart for SNR tweaking, my snr is set at 12 by engineer so the lowest i can get my SNR down to is 7 by entering 1 in box, i know my line will go lower as it was tweaked before using my netgear, is there anyway to drop it more or is 5 the most you can drop it by

kenny

[billion_fan]

This is a strange one, on my line the target SNR is set to 3.5db (ISP Be, set to gaming profile), my SNR setting is set to 3.5(this was the best settings, as 1/2/3 settings would not sync on my line) once I set my SNR to 3.5 on the 7800DXL the SNR downstream value shows as 1.1db, last night was 0.6db, so I know the router can hold a low SNR.

Have you asked your ISP to see if they can set a target SNR to your line to 6.db?

I might have to talk to our engineers about this too see what we can achieve. (this will have to be tomorrow as just got home)

[kenny70]

thanks for reply some more info

my dg834gt with the dgteam firmware was tweaked down to a snr 4 from the 12 set by engineer, get a good few errors but the line never dropped once in over 4 months, asked before if they would drop it but only engineer can ask for that they say, its no big deal but it would be nice if 7800dxl allowed the same snr tweaking as 7800n does

kenny

[billion_fan]

thanks for reply some more info

my dg834gt with the dgteam firmware was tweaked down to a snr 4 from the 12 set by engineer, get a good few errors but the line never dropped once in over 4 months, asked before if they would drop it but only engineer can ask for that they say, its no big deal but it would be nice if 7800dxl allowed the same snr tweaking as 7800n does

kenny

I'll speak to our engineers to see what we can do, by the way what is sync speed like on the 7800dxl with a SNR of 7db compared to the netgear with the SNR reading of 4db.

[Spudgun]

Does it not work in the same way as the 7800N?

See this table for info - http://www.increasebroadbandspeed.co.uk/billion-7800n

If the OP wants to reduce his SNR from his ISP's default of 12 to a more standard 6 would he not put 65550 in the box in the DXL settings screen?

If we wants to go further and reduce it from 12 to 4.5 then 65525 would do the trick

[kenny70]

tried the same way as 7800n but didnt work but will try again


not much of a diff between 7 and 4 around about 400kbps but then my broadband tends to be up and down a bit, going to reset to default and leave for a few days

[swatboy79]

I have found that i have to set my BE provider settings to 6db target in order to get the SNR settings to appear to work as an exact absolute value.

I have found it works is like this:

my sink | snr setting | result
6db | 6db | 6db sync (so 6db settings = a -0db)
6db | 5db | 5db sync (so 5db settings = a -1db)
6db | 4db | 4db sync (so 4db settings = a -2db)
6db | 3db | 3db sync (so 3db settings = a -3db)
6db | 2db | 2db sync (so 2db settings = a -4db)
6db | 1db | 1db sync (so 1db settings = a -5db)

because of this If i sync set at 9db, the target value isn't absolute anymore its rather a subtracting value (because that is exactly what it is. If you subtract 6 off of your SNR setting that's what it will subtracted from your ISP's SNR setting. so 6 - 6 = 0; 5 - 6 = -1; 4 - 6 = -2; etc)
(e.g 9db sink at a 6db setting will result in 9db sync {a -0db})
(e.g 9db sink at a 5db setting will result in 8db sync {a -1db})
(e.g 9db sink at a 4db setting will result in 7db sync {a -2db})
(e.g 9db sink at a 3db setting will result in 6db sync {a -3db})
(e.g 9db sink at a 2db setting will result in 5db sync {a -4db})
(e.g 9db sink at a 1db setting will result in 4db sync {a -5db})

for billion_fan - at 3db ISP SNR, the lowest number that would work would therefore be a 4db setting as this is really -2db (3db-2db=1db result), anymore than that would result in a 0db or less sync....

I don't really have a problem with this as i can set my provider SNR to 6db (out of a possible 3/6/9db) but for other people out there i guess the setting isn't quiet absolute as it is presented to be.

However, this is an awesome setting and makes far more sense than the old 7800N way which was really just a factor.

[billion_fan]

I have found that i have to set my BE provider settings to 6db target in order to get the SNR settings to appear to work as an exact absolute value.

I have found it works is like this:

my sink | snr setting | result
6db | 6db | 6db sync (so 6db settings = a -0db)
6db | 5db | 5db sync (so 5db settings = a -1db)
6db | 4db | 4db sync (so 4db settings = a -2db)
6db | 3db | 3db sync (so 3db settings = a -3db)
6db | 2db | 2db sync (so 2db settings = a -4db)
6db | 1db | 1db sync (so 1db settings = a -5db)

because of this If i sync set at 9db, the target value isn't absolute anymore its rather a subtracting value (because that is exactly what it is. If you subtract 6 off of your SNR setting that's what it will subject from your ISP's SNR setting. so 6 - 6 = 0; 5 - 6 = -1; 4 - 6 = -2; etc)
(e.g 9db sink at a 6db setting will result in 9db sync {a -0db})
(e.g 9db sink at a 5db setting will result in 8db sync {a -1db})
(e.g 9db sink at a 4db setting will result in 7db sync {a -2db})
(e.g 9db sink at a 3db setting will result in 6db sync {a -3db})
(e.g 9db sink at a 2db setting will result in 5db sync {a -4db})
(e.g 9db sink at a 1db setting will result in 4db sync {a -5db})

for billion_fan - at 3db ISP SNR, the lowest number that would work would therefore be a 4db setting as this is really -2db (3db-2db=1db result), anymore than that would result in a 0db or less sync....

I don't really have a problem with this as i can set my provider SNR to 6db (out of a possible 3/6/9db) but for other people out there i guess the setting isn't quiet absolute as it is presented to be.

However, this is an awesome setting and makes far more sense than the old 7800N way which was really just a factor.

Nice post should help others looking to tweak the SNR

[swatboy79]

Back onto this whole SNR thing..

If a line is set at 12db sync rate for example then by following my finding the lowest you could reduce
it would be 12db - 5db = 7db. There is no possible setting therefore to get a 12db line to 3db as a value of 1 would just bring it to 12db - 5db = 7db?

Could we get billion to confirm my finding of the number not really being absolute (unless your SNR sync happens to be 6db) and what would happen if
we had lets say a 12db sync what would we do if we wanted that to be at 3db?

Why does the SNR behave this way currently with only a maximum of a -5db subtractor and how come the setting is not an absolute figure?

Just wondering as after BE provider dissolves up and i have to move to a provider that does not have a settable SNR value on their end.

[kenny70]

That's the only problem and frustration I have with the 7800dxl if I had known it was to be limited SNR tweak then I would have went for the older model and saved some money, right now im very close to plugging my netgear 834gt back in as I can tweak that all the way down to 3, yes some say its a bit complicated but if you cabt work it out should you really be playing with SNR in first place.

So what chances of an update to allow us who don't have a perfect 6db being able to tweak it as required for me that's going from 12 down to 3?