Recently I have had weeks of constant dropouts and have been frustrated at the unreliability and as this has now been fixed I thought I would share the outcomes.
Firstly, everything was setup correctly and some days the internet worked fine - other days it was terrible.
The NBN service team attended my house and found that the link to the modem was fine but there were 2 main issues.
1. We had 2 phone connections in the house - the 2nd one must be disconnected to ensure reliability.
2. The main reason was that our connection was an older overhead connection - when it is windy it was simply losing it's connection, ensure that this is replaced.
Hope this helps.
Thats GREAT to hear.
'Star Wiring'' inside homes is a common fault. It was barely ok with ADSL, and just plain makes NBN-FTTC/N services very unstable.
Having 1x internal phone line is the best thing to have.