Be 6dB? 3dB?
- Thread starter Tomsk
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Man of Honour
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- 16 May 2005
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It's simply a target number for the signal-to-noise-ratio (SNR) of your line.
The lower the SNR, the higher your connection can sync.
Some lines are better quality than others, so your line may be stable with a lower SNR...or not.
Only thing you can do is try it and see where you can get to before your line becomes unstable.
One thing to note: Sometimes your line will seem stable in terms of maintaining a sync/connection, but it may be getting so many errors "behind the scenes" that your lower SNR and higher sync/connection speed is actually performing slower than it would do if you had a higher SNR. Once again, all you can do is test and keep an eye on your error count in the router.
The lower the SNR, the higher your connection can sync.
Some lines are better quality than others, so your line may be stable with a lower SNR...or not.
Only thing you can do is try it and see where you can get to before your line becomes unstable.
One thing to note: Sometimes your line will seem stable in terms of maintaining a sync/connection, but it may be getting so many errors "behind the scenes" that your lower SNR and higher sync/connection speed is actually performing slower than it would do if you had a higher SNR. Once again, all you can do is test and keep an eye on your error count in the router.
It's the target SNR margin rather than raw SNR that you're interested in, but the BeBox is pretty useless at counting errors.
What you need to watch out for is your SNR margin fluctuating over time - the higher your SNR margin, the bigger insulation you have from that making your connection crap out.
What you need to watch out for is your SNR margin fluctuating over time - the higher your SNR margin, the bigger insulation you have from that making your connection crap out.
They change the target SNR at their end. Your modem will resync and set the sync rate as high as possible while keeping your SNR at 3db. End result is your sync rate will increase but your line could potentially be a bit more unstable.
If your SNR is 8db right now, you'd find your speed would increase slightly if you resync right now as it'll sync up with your target SNR as 6db. SNR fluctuates during the day. It just means that when the line conditions get worse (as they often do in the evenings) your chances of seeing a loss of sync are higher.
I have a downstream attenuation of 27db which has got me around 18 to 19mbit ish on a 6db profile. I tried a 3db profile and this got me over 20mbit, but the line was dropping out occasionally and there were a hell of a lot of errors (though as Tolien says, the BeBox router is known for reporting these stats wrong). In the end I just went back to 6db as my line clearly isn't good enough for it.
If your SNR is 8db right now, you'd find your speed would increase slightly if you resync right now as it'll sync up with your target SNR as 6db. SNR fluctuates during the day. It just means that when the line conditions get worse (as they often do in the evenings) your chances of seeing a loss of sync are higher.
I have a downstream attenuation of 27db which has got me around 18 to 19mbit ish on a 6db profile. I tried a 3db profile and this got me over 20mbit, but the line was dropping out occasionally and there were a hell of a lot of errors (though as Tolien says, the BeBox router is known for reporting these stats wrong). In the end I just went back to 6db as my line clearly isn't good enough for it.
