I notice in the second picture how low the downstream snr is for what was presumably an 8c service.....
It was indeed 8c at the time the photo was taken.
SNR never gets much above 6dB.
This is from the modem itself, today:-
Retrain Reason: 2
Max: Upstream rate = 5757 Kbps, Downstream rate = 33852 KbpsPath: 0, Upstream rate = 5771 Kbps, Downstream rate = 29475 Kbps
Link Power State: L0
Mode: VDSL2 Annex BVDSL2 Profile: Profile 17a
TPS-TC: PTM ModeTrellis: U:ON /D:ON
Line Status: No DefectTraining Status: Showtime
Down UpSNR (dB): 5.8 6.0
Attn(dB): 0.0 0.0Pwr(dBm): 12.3 6.3
& these are the other stats from the modem, again from the same time today (07:00):-
Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783) DS: (32,859) (1216,1963) (2792,3939)
Medley Phase (Final) Band PlanUS: (0,95) (868,1207)
DS: (32,859) (1216,1963) VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 5757 kbps 33852 kbpsActual Aggregate Tx Power: 6.3 dBm 12.3 dBm
============================================================================ VDSL Band Status U0 U1 U2 U3 D1 D2 D3
Line Attenuation(dB): 8.3 53.3 64.1 N/A 21.6 63.4 0.1 Signal Attenuation(dB): 14.5 52.6 N/A N/A 21.6 63.4 N/A
SNR Margin(dB): 5.9 6.0 N/A N/A 5.6 5.9 N/A TX Power(dBm): -4.4 5.8 N/A N/A 11.0 6.3 N/A
Unlike a JDSU, the modem reports a connection's attenuation values for each band plan rather than an overall value & I don't know how to convert my modem stats to the equivalent JDSU reading.
Can you glean anything from those stats such as attenuation too high, SNR too low, Power too low etc. to suggest why I cannot maintain a connection much above 30Mb sync speed?
I got 35Mb sync speed when FTTC was first installed on the 8c profile back in June 2011.
My "real" distance from the cabinet is probably 850m (as one engineer reported from BT's Network Records via his laptop), but JDSUs have variously reported it as 900m, 1000m, 1100m.
My ISP has very recently put me on their 80Mb/20Mb trial, just as an experiment on a sub-40Mb connection - to see what (if any) difference it made.
As we suspected, as I get nothing at all from the higher 17a DS band plan (tones (2792,3939) ), it has made no difference whatsoever.
Edited by Bald_Eagle1 (Thu 22-Mar-12 22:36:29)