Which type of NBN are you on? What is your plan?
Are you doing video-conf from a computer connected by cable or by wifi device?
Wifi will get faster the closer you are to the router.
Do you use 2.4G or 5G band? Changing wifi channel might help.
Other wifi devices can cause slow response.
Other networks in the neighbourhood can cause interference. Can your wifi device see other networks?
Have you tried the speed test on TPG's support page?
