SNR Drops Under Load??

When I'm downloading my downstream SNR goes from 6.3db down to as low as 5.6db...

Is this normal??

When I'm downloading my downstream SNR goes from 6.3db down to as low as 5.6db...

Is this normal??

Does it actually affect any of the connections functionality ????

If that's a no, (and I'll wager it is) then stop fretting, go out, enjoy the sun.

Well it seems to make the connection less stable than it used to be...

BQM also seems to be a lot more jittery that it used to be when downloading... actually I remember the BQM staying pretty smooth when downloading at high speed, it was only uploading that upset the BQM...

and I'm not sure but would say DLM won't look kindly on my SNR going from 6.4 - 5.6 and hopping up and down during the time the connections under load.

I think your reply is harsh, he didnt ask if he should stop worrying about it.

To the OP its definitely not normal, it would suggest maybe when the router/modem is more busy its increased power draw is interfering with the signal. Or possibly the device downloading to its higher processing is the source of interference.

I would make sure power cables are not tangled up with any other cables, if you have separate router/modem close to each other maybe move them further apart. IF these options are not available then do some diagnosis with swapping out equipment.

DLM wont care about your snr margin, it will only be bothered if your ES rates get too high or if you have too many lost sync events.

Also using BQM for diagnosis for this is not a good idea, downloading creates utilisation and yes can cause jitter, especially without bandwidth policies.

Why have you chose to not make your VDSL TBB BQM public?

Edited by Chrysalis (Tue 29-Mar-16 06:20:47)

My SNR has plummeted to 2db on downstream while up seems barely affected meaning next time my modem resync's I'm going to be losing 15+Mb/s....

How does this happen in a matter of hours.... Now extremely dissapointed... and not looking forward to the arguing with BT I'm gonna need to do to get this sorted ''

I think this might be something to fret about now

Yesterday's Stats:

lcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 24114 Kbps, Downstream rate = 78100 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 78564 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Discovery Phase (Initial) Band Plan
US: (7,32) (871,1205) (1972,2782)
DS: (33,859) (1216,1961) (2793,3959)
Medley Phase (Final) Band Plan
US: (7,32) (871,1205) (1972,2782)
DS: (33,859) (1216,1961) (2793,3959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 24114 kbps 78100 kbps
Actual Aggregate Tx Power: 7.1 dBm 13.4 dBm
====================================================================================
VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
Line Attenuation(dB): 4.6 22.1 33.1 N/A N/A 11.7 28.6 43.7
Signal Attenuation(dB): 4.6 21.1 32.3 N/A N/A 13.2 28.4 43.7
SNR Margin(dB): 16.1 15.7 15.5 N/A N/A 6.3 6.2 6.3
TX Power(dBm): -2.5 -21.5 6.6 N/A N/A 10.2 7.9 7.0

Today's Stats:

xdslcmd info --pbParams
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 22253 Kbps, Downstream rate = 63720 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 78564 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Discovery Phase (Initial) Band Plan
US: (7,32) (871,1205) (1972,2782)
DS: (33,859) (1216,1961) (2793,3959)
Medley Phase (Final) Band Plan
US: (7,32) (871,1205) (1972,2782)
DS: (33,859) (1216,1961) (2793,3959)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 22253 kbps 63720 kbps
Actual Aggregate Tx Power: 7.1 dBm 13.4 dBm
====================================================================================
VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
Line Attenuation(dB): 4.6 22.1 33.1 N/A N/A 11.7 28.6 43.7
Signal Attenuation(dB): 4.6 21.2 32.1 N/A N/A 13.2 28.4 43.7
SNR Margin(dB): 13.3 12.5 12.5 N/A N/A 2.4 2.4 2.4
TX Power(dBm): -2.5 -21.5 6.6 N/A N/A 10.2 7.9 7.0
#

What the hell has gone wrong???

I see now you on g.inp, has this helped at all?

Been on G.INP for months now, since it was still showing 100+attainable....

I had to resync the modem this morning, There was errors occuring and streams kept dropping, I think G.INP as now been enabled on upstream as a result.

This is my speed now compared to 72/18 on Thursday

Edited by mlmclaren (Sat 02-Apr-16 12:34:50)

What are your speed estmations on the DSL checker?

Looks like you may need an engineer visit.