The Australian network the NBN is replacing is predominately copper with an overlay of fiber that is provided by a number of Carriers. The term “fibre to the Node” (FTTN) is where the NBN run a fibre connection to a node (connection point) in your street and then the existing copper cable to your premises. Depending on the quality and length of this copper cable will determine it’s performance. It is a “Best Efforts” environment.
In some cases with business locations where a desired speed and performance is required, several copper cables are bonded together. This generally tops out at 20MB/20MB. Depending on where your premises is situated in the network will depend on what technology either copper or fiber is available.