In reply to a post by simon194:

Like this one from taken from my modem. Bit Loading Plot

You're doing better than mine Bits graph

# xdslcmd info --pbParams 
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason:	0
Max:	Upstream rate = 9867 Kbps, Downstream rate = 58564 Kbps
Path:	0, Upstream rate = 10049 Kbps, Downstream rate = 49161 Kbps

Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783) 
DS: (32,859) (1216,1963) (2792,3959) 
Medley Phase (Final) Band Plan
US: (0,95) (868,1207) (1972,2783) 
DS: (32,859) (1216,1963) (2792,3959) 
       VDSL Port Details       Upstream        Downstream
Attainable Net Data Rate:       9867 kbps         58564 kbps
Actual Aggregate Tx Power:        4.8 dBm          12.2 dBm
============================================================================
  VDSL Band Status        U0      U1      U2      U3      D1      D2      D3
  Line Attenuation(dB):	 6.2	 33.5	 49.7	  N/A	 16.0	 41.1	 62.2	
Signal Attenuation(dB):	 8.9	 32.5	 47.6	  N/A	 16.0	 41.1	 62.2	
        SNR Margin(dB):	 6.2	 6.0	 6.0	  N/A	 6.4	 6.4	 6.6	
         TX Power(dBm):	-4.4	-9.2	 4.1	  N/A	 9.2	 7.8	 3.6

In reply to a post by simon194:

Part of the lower band can be shared apparently. They show up on the bit loading plot I posted above.

I'm afraid that proves nothing, as our two sources are the same scripts. Yours is merely the graphical representation of the (similar) figures that I gave. Which is not to say there cannot be sharing, but to me that is counter-intuitive.

I do not doubt the scripts themselves. I do question the data returned by the HG612. We know for a fact some of the other stuff is incorrect, although most appears valid. In particular it can show FECs on Fast Path.

The scripts show the "shared" or overlapping tones in blue.

From my observations, I have deduced the following:-


As the HG612 NEVER displays any US data for QLN, Hlog & SNR when connected to a Huawei DSLAM, the blue data that is shown MUST be used for DS bitloading.

However, ECI DSLAMS do SOMETIMES report US QLN. Hlog & SNR data to the HG612 modem.

Most times it can still be assumed that the blue tones are used for DS bitloading.

A few connections (very close to the cabinet) do not use US0 band for upstream bitloading at all as maximum speeds can be obtained via the US1 & US 2 bands alone , thus for those connections the "shared" tones are definitely made available for DS bitloading.

In reply to a post by Bald_Eagle1:

The scripts show the "shared" or overlapping tones in blue.

From my observations, I have deduced the following:-


As the HG612 NEVER displays any US data for QLN, Hlog & SNR when connected to a Huawei DSLAM, the blue data that is shown MUST be used for DS bitloading.

However, ECI DSLAMS do SOMETIMES report US QLN. Hlog & SNR data to the HG612 modem.

Most times it can still be assumed that the blue tones are used for DS bitloading.

A few connections (very close to the cabinet) do not use US0 band for upstream bitloading at all as maximum speeds can be obtained via the US1 & US 2 bands alone , thus for those connections the "shared" tones are definitely made available for DS bitloading.

Looking at the SNR plot the first blue area on the bit loading plot is in the downstream area but a majority of the 2nd is in a gap between DS0 and US1.

FWIW, here's some band plan data from unlocked ECI & HG612 modems - from the same user on the same ECI DSLAM connection:-

From the ECI modem:-

(00,(0010,0031),(0010,0031))
(01,(0882,1193),(0882,1193))
(02,(1984,2770),(1984,2770))

(00,(0033,0857),(0033,0857))
(01,(1218,1959),(1218,1959))
(02,(2795,3950),(2795,3935))


From the HG612:-

Discovery Phase (Initial) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959) (2792,4083)

Medley Phase (Final) Band Plan
US: (0,95) (880,1195) (1984,2771)
DS: (32,859) (1216,1959) (2792,4083)

As these are very early days of looking at any stats from an unlocked ECI modem, there is no guarantee about the reliability of any such obtained data.

At some stage & when I have a bit more spare time, I hope to test an unlocked ECI modem on my Huawei DSLAM connection for comparison against the HG612.

Edited by deleted (Mon 22-Oct-12 19:38:06)