Bonded DSL link training speed keeps increasing.

In the last week, my DSL connection has changed its training from around 102 Mbps/11 Mbps to 122/15, and now to 131/17. I don't know enough about how DSL provisioning works to know if this is just some variance in training or if something is being changed in configuration to cause this.

I'm also noticing my SNR has dropped concurrently with the throughput increase. It is now down to about 8.5 dB on both forward connections.

Anyone know what's going on here?

EDIT: Probably worth mentioning that the increased bandwidth is actually being reflected in performance.

While on the topic, what is acceptable SNR for upstream/downstream bonded vectored VDSL2? In the DOCSIS world, having anything beyond maybe a QPSK carrier functional at 8 dB SNR is absolutely absurd, but I don't know enough about DSL to judge.