and don't quote me, but I'm sure Exetel changed a couple years back, now no public IP. They used to be good 10 years ago public and static IP, after JL's passing a lot of negative changes made to their network and i'm sure this is one of them
Probably 4/5 years old, was more an example of it can be done... pretty sure Telstra and Optus can still provide same, but you may need a business plan and have to call them to have it activated. This mob does; https://summitinternet.com.au/internet-data/telstra-4g-data/ As does this one; https://www.zetta.net.au/services/internet/mobile-broadband/ JSmith
If it's for a business, Optus will sell you postpaid business plans with static IPs too. Probably Telstra as well, although they're making it increasingly clear they don't give a fuck about any entity with less than 7 figure annual bills. similar, but not identical, options to ngrok are zerotier and tailscale. depends on what the OP's trying to achieve
Take your Telstra sim card into a Telstra Business Centre and plead your case, they can add the extranet codes for you!
All mobile broadband are on cgnat just not enough ip to go around. I was looking for a similar solution a year ago, ngrok + raspi solved all my problems. If this is roughly what you are after https://forums.overclockers.com.au/...urce-4g-modem-possible.1272980/#post-18343532