Hi John,

...

On topic : maybe ip will not the protocol to be used for this type of communication (v4 or v6), so this discussion might not be relevant

That’s actually an excellent question - perhaps these are supposed to specialized address space and not general purpose?

Are these addresses going to be using standard IPv6 protocol or something else? Also, is this actually public space, i.e. is intended that existing Internet service providers may send/receive traffic to these prefixes?

The intent is for standard issue IP addresses. The goal is to deliver any and all Internet services that are practical given the high-latency intermittent links. SMTP is my favorite example. If we do it right, that should Just Work. Yes, there would be major firewalls between space and the general Internet, but this is no different than any other enterprise network. Internally, the agencies would like to use common off-the-shelf networking as much as possible. Thus IP and QUIC seem like a good starting point. Regards, Tony