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[pintosal]

I've been monitoring my Billion Bipac 8800NL with DSLStats, and the setup is performing well.

However, today I noticed something strange, as on the attached graphs.

The attainable down and up rates jumped up at around 08.55, in step with the SNRM, and then fell back down again.

I would have expected the SNRM to fall when the attainable rates increase

Am I being thick?

What might cause the increase and subsequent fall in attainable rates?

The FEC chart does not show anything unusual.

[roseway]

If there wasn't a resync, then a temporary increase in the SNRM would be expected to give a corresponding increase in the attainable speeds. It would have been the result of a reduction in interference, very possibly a reduction in crosstalk caused by a neighbour switching off for half an hour or so.

[pintosal]

If there wasn't a resync, then a temporary increase in the SNRM would be expected to give a corresponding increase in the attainable speeds.

I'm still puzzled.

I keep thinking back to when my line was ADSL and my Netgear DG834T was running the DGTeam firmware.

To increase the download speed you had to reduce the SNRM, but your reply implies the opposite.

[roseway]

What you were doing with the DGTeam firmware was reducing the Target SNRM, i.e. the value which is used in the negotiation between the modem and the DSLAM. The target SNRM is the safety margin, and if you reduce the safety margin the speed increases.

But if the amount of interference reduces, then the SNRM increases. If you had forced a resync at that point, a higher connection speed would have resulted and the SNRM after that would have been back down to close to its target level. That's what the attainable speed tries to indicate.

[pintosal]

Thanks for explaining it so clearly.

I was confusing cause with effect.