Sorry, if it makes you feel better, I am in New Zealand and port fowarding has somehow been turned off (games like arma hosting a server do not work and third party port forward checkers say it is turned off) I just send that port forwarding link off to the rest of the world in the hope that it works... for others....
What city in Australia?
There are quite alot of things that can be affecting this.
But usually the biggest culprit of them all is carrier grade NAT, this is some pure EVIL invention to prolong the life of IPv4... the problem with IPv4 is that we have limited amount of addresses, and these where given out freely in the beginning, so North America and Europe got alot of these, and then the rest of the world not so much....what this means for you as an internet user, is if you are in parts of the world with "fewer" IPv4 addresses, is that your ISP must use different variants of tricks to let many users users share one IP address.... Carrier Grade NAT does this on a whole bigger level than what any ordinary home router does it.
But the thing is that every extra layer of NAT, makes is harder and harder to port forward traffic to your computer, and since Elite Dangerous is using Peer-to-Peer techniques to do instance traffic between players in the same instance, then you can see how this can be a bit problematic if several of the players in the instance cannot accept incoming traffic, due to all the shenanigans of multiple levels of NAT. And this will block your port forwarding....
So what can over come this kind of things?
Well having atleast one player in the group on a public available IP usually helps, if this player is the instance "master", then everyone connects this player and everything is perfect. So your wing, or multicrew session is fine and then you go to a new location and enters an existing instance, with a player that cannot accept incoming connections. Now you are in trouble....
Then add to this, that Australian, New Zeeland players are more likely to be put in same instances, than with European, North American players. Due to geographical preferences, where the logic behind this is that you should have better connections with players closer to you geographically, than to those that are on the other side of the globe, as passing packets back and forth between players takes time,and the longer the distance the longer it takes.
But if you use a VPN service in North America/Europe, you will a public IP in those regions, and are more likely to connect to players that have working incoming traffic and things will be better for you. Despite the previous statement about network time, and to top it all off, if you are all using the same VPN service, it could even make the multicrew stuff to work better. Also depending on the VPN it will probably support client tricks to allow incoming traffic making this even better.
I do not know about good VPN services, that are used. Only that several players have discovered that VPNs usually improves their instancing problem, like people who had VPN to access American Netflix...
So VPN is the short term solution
The long term solution is to wait for the adoption of IPv6, and here comes the crux of the problem, Since North America and Europe have so many IPv4 addresses, they are in no hurry in adopting IPv6, while many ISP in Asia have adopted IPv6 due to very limited availability of IPv4 addresses, out of need. But since Europe and North America have no shortage, yet, of IPv4, they drag their legs behind in adopting IPv6....
The above is a very simplistic explantation of the problems players from New Zeeland and Australia encounters (and of course other countries with limited amount of IPv4 addresses)...
