Caller: Indian scam NBN call center

Saying they are NBN offering "free fibre upgrade". They want you to do a speedtest, then want you to download a remote destop software (team viewer, anydesk etc.) and install it. I never go past this point, as a tip to anyone wanting them to go away say your computer (desktop or laptop) is Linux. They are then stuck as they only know how to scam people with Windows or Mac based computers, say Linux and bam they hang up. Works everytime. You can tell its a scam as there is the delay between you saying hello and them talking (after a tiny beep), but I like wasting their time so I play along, but you can usually hang up as soon as you hear the delay in answer and the noisy background call centre noises that these Indian call centres always have.