I have a bit of confusion regarding vigors 2860's reporting of rate attainable, rx speed and speed testing.

My SNR has been 6db's for a least two months, with a attainable speed of 14mbs, and a download speed of 11mbs
Speed tests have been steadily decreasing from around 12mbs to 9.5mbs.

This situation has been confirmed by using the ISP's modem, the only difference is that the line attenuation is lower by about 2db than vigors reporting of attenuation.

Both modems are in the same location, using the same cabling (obviously not at the same time!!)

Yesterday all of a sudden the SNR step increased to 12db, maintaining this overnight, then dropped to 9db.
The attainable speed step increased to 17mbs, and is still the same, 17mbs.
The download speed is reported as 11mbs
However, speed tests still are sub 10mbs

The only change to the vigor is the upgrade to 3.8.6_BT, which occurred prior to the SNR/attainable speed increase.
The DSL Version is 572801_A HW: A

The service is adsl2+.

Why hasn't the attainable speed and speed test increased?

How does the vigor calculate the SNR, attainable speed and rx line speeds?

Has anybody else experienced this?


Thanks

Aimee the Confused

PS it did it again over the weekend, then back to the 'Normal' settings. Is it the vigor doing this or BT/OR