Re: @Lee D
Hmmm. There is something going on that I didn't think could happen.
I have just spent the last few hours since I posted here testing on my 2 PC's and my 2 ED accounts.
With UPNP turned off and no port forwarding ED worked as it should. I could see other CMDRs in Open. I could also Wing up or MultiCrew with my other account.
In fact after turning off UPNP (guilty) and ED still working I thought that my DrayTek router needed rebooting for it to kick in, but it was the same afterwards.
Much has been made of Frontier's decision to use p2p for the networking between clients and they do use a central server for some transactions, but clients do talk directly to clients. This is why combat logging is a thing. This post does explain quite well how ED's networking happens:
https://forums.frontier.co.uk/showthread.php/238233-VERY-basic-guide-for-ED-networking
A Google search will come up with a lot of pages about Elite Dangerous Networking Issues, so it doesn't work for some people as well as we all would like it to.
The latest update also includes new settings for networking in Options that include port forwarding.
So, I would say it can work well for some people depending on their router, but there's no doubt that others have problems that can be fixed by port forwarding or having UPNP enabled.
Fly safe CMDRs
(ED Kickstarter backer, Founder level)