TM no longer cap solely based on ADSL line rate.
Most users will show 1024 to 2048kbps downstream line rate but the actual speed will depend on the packages paid for.
as for your disconnection problem, its due to the low SNR Margin on your downstream link.

a single digit SNR is NEVER good. SNR about 20db or above should be very stable. Between 10-19 is just marginal with the tendency to drop on high usage scenarios or where error rates will be high resulting in lower effective throughput.