Kitz Forum
Broadband Related => Broadband Hardware => Topic started by: dazmatic on August 17, 2021, 04:19:00 PM
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Hi all,
I live out in the middle of the sticks at the end of a line.
That being said, I'm able to get sync speeds of VDSL2 at _around_ 38/9Mbps which I thought was quite good but the SNR ratio is poor, 3.8dB down and 6.3dB up.
That being said, I'm only getting about 30Mb down with the VMG3925 router and 33ish with a HG612. I believe I'm on a Broadcom cab too so I'm surprised to see that the VMG3925 to get a slower connection.
EE are being they're helpful selves by saying that there's no fault on the line but because I don't have their router plugged in, there isn't much more they can do.
Any ideas?
Thanks.
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Some variation between hardware is just to be expected, its why many of us on the forum have tried different hardware and use whatever works best.
I also wouldn't call 3.8dB SNRm "poor". Anything that's within the tolerances of the dynamic line management by definition functioning as designed.
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@dazmatic welcome to kitz forums
What's stating you will get 38/9?
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I understand that there will be differences in hardware, just surprised that's it's backwards to what I've read.
The 38/9 is what's apparently attainable on my line according to the router, both the HG612 and the VMG3925 say similar things, just that the VMG actually throughputs less.
EE wanted me to plug in their router so they can pull some stats off it but I plugged it in, tried getting it to work with my existing network but it was a no go, their router doesn't allow bridge mode and there's no way I'm reconfiguring my network so that they can get stats for a couple of days.
Am I just clutching at straws here chasing a few Mb? I saw the 3.6dB SNR and was a bit concerned because that's quite low.
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Am I just clutching at straws here chasing a few Mb? I saw the 3.6dB SNR and was a bit concerned because that's quite low.
The target SNRM starts at 6dB but if a line is stable the DLM will lower the SNRM as low as 3dB.
You would sync nearer 30Mb i6s the SNRM went back up to 6dB.
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Thanks.
Am I reading this wrong then? I was under the impression that a low SNR = bad and high SNR = good?
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Thanks.
Am I reading this wrong then? I was under the impression that a low SNR = bad and high SNR = good?
SNR is a balancing act between the target that DLM identifies for your line and your line's stability at that target. A lower target i.e. 3db will get you a higher sync rate than 6db but your line has less margin before it hits a point where errors overwhelm it and the connection drops entirely and a re-sync is needed. SNR fluctuates throughout the day and throughout the year due to changing environmental conditions and a problematic line is likely to suffer more than a more stable one which is why a higher target helps as your further away from the point of a possible re-sync which is what DLM attempts to achieve when your line hits a certain threshold of errors or disconnects.
So a low actual SNR could be considered bad in that there's less wiggle room before it hits the bad spot of errors and disconnects but a lower target SNR will allow for a greater sync speed
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I wouldn't pay too much attention to the 'attainable' numbers the routers are giving you as they often miscalculate them. If your downstream SNR is 3.8dB then you are most likely on a Huawei cabinet with G.INP doing its job to get you the best sync rate available.
As said there will be differences between devices, and if the HG612 is giving the best results on your line then I'd carry on using that.
:)