Tones in use

I have "lost" the top end usage ...

My modem was negotiating usage of all tones and D3 covered 2793 up to 4095 or 4096 (or similar). I have just noticed that DSLStats is now reporting D3 from 2793 to 3970. SNR at tone 3970 is 17dB. No apparent reason for te change.

What are others seeing for D3? Highest tone and SNR figure.

Has your cab changed from an ECI to a Huawei?

Always been Huawei

Perhaps a line card upgrade for vectoring?

Interesting question...

I've had 3 different FTTC lines over time.

Line 1, Huawei DSLAM, 650m, 40M
12/2011: Tone 2792-3939 in medley, last SNR is 15dB at 3609, last bitloading is 1 at 3692.

Line 2, Huawei DSLAM, 375m, 80M
02/2012: Tone 2792-3939 in medley, last SNR is 22dB at 3938, last bitloading is 4 at 3938.
06/2012: Tone 2792-3959 in medley, last SNR is 21dB at 3959, last bitloading is 4 at 3959.
11/2013: Tone 2793-3970 in medley, last SNR is 23dB at 3970, last bitloading is 4 at 3970.
06/2014: Tone 2793-3970 in medley, last SNR is 20dB at 3970, last bitloading is 3 at 3970.
10/2014: Tone 2793-3970 in medley, last SNR is 21dB at 3970, last bitloading is 4 at 3970.

Line 3, Huawei DSLAM, 120, 80M
02/2015: Tone 2793-3970 in medley, last SNR is 32dB at 3970, last bitloading is 6 at 3970.
09/2015: Tone 2793-3970 in medley, last SNR is 35dB at 3970, last bitloading is 7 at 3970.

Note: Tone range has always been identical for both discovery and medley.

My top-end has altered earlier in the rollout, but has never been higher than 3970.

Thanks for that.

I started looking when I suddenly lost 7Mbps from my downstream achievable rate! I am now synced at 79999 with am achievable of 753xx. BT Wholesale tester returns 77.xx Mbps!

I am fairly certain it was previously up at 4095 (or so) and now 3970. Searching around I have found a few occurrences where close to tone 4096 are reported such as http://forum.kitz.co.uk/index.php?topic=13328.5;wap2 I am sure I have some screen shots from previous however I connot locate them

QLN - slowly drifts down to -135.000 at tone 3971 then off a cliff to -160 at tone 3972 onwards, Hlog -49.5000 at tone 3970 then -96.00 for 3971 onwards, SNR 16.875 at tone 3970 then 0.00 from 3971 onwards ... just seems rather ODD.

The spec for Profile 17a take D3 up to tone 4096 at 17.66 MHz so it should be capapble.

In two minds whether to reboot the modem of leave as is to see if it recovers.