I don't have the patience to wait on-hold, nor to have to call-back multiple times, for the amount of time required to ask this question of optus technical support, but, basically, I moved into a house in melbourne a couple years ago, and got cable through optus, as ADSL2/2+ on the DSLAM coverage map was listed as basically useless.
My cable was awesome, i had 30mbps downspeed connection during off-peak times, and dropped to about 26 during peak. I have since moved 5km around the corner, and lived in this house since about February. My connection here is awful. When we first moved, it was somewhat usable, but would sit at around 6mbps during early night periods, and drop to about 3mbps during full peak (latency was still high enough that general connectivity was slow). In the last couple weeks it has become unusable. I average about 2-3mbps all night and on weekends. During off-peak (i was at home sick for 2 days last week) it was perfect, I had 30mbps downspeed, but using it after work, and on weekends, it is now basically not usable, even a google search takes a while to load the results.
I tried playing around with the cable modem connection frequencies in the hope that different channels may be less loaded, but this resulted in no change.
I guess what i really want to know, since with this usage, I really shouldn't even have to pay full price considering optus have quite clearly overloaded their exchange/node with too many users, is there anything I can do to improve performance, or to actually verify that its the exchange connection and not a dodgy cable installed to my house?
I imagine Optus have long since halted most works on their cable. They no longer own it and it is due to be completely junked in a year or so anyway. You need to contact tech support and get them to run some line speed tests on your line (which they can do then and there) and tell you what speeds they think you can get. They'll probably take you through a hard and soft reset of your modem etc. Maybe it will fix things? They may also arrange for somone to come out and test your line at your home.
Otherwise IMO there's not a lot you can do - when does the NBN reach your postcode?
Thanks for your response. It shouldn't be a modem issue, i already hard reset my modem and router to rule out those as an issue. I guess I'll just bite the bullet and call them and get them to do a line test. NBN not due in my area till apr-jun 2018.