[arin-ppml] Draft Policy ARIN-2026-1: Taking IP To Other Planets (TIPTOP)

[Tony Li]

Hi Joe,

> Considering appendix A of deepspace-ip-assessment, why
> does this policy speak to IPv4 at all?


Because there are some other pragmatic issues that I think that we’ve touched on before.  

Today, space agencies are already using IPv4 addresses for all of the usual legacy reasons. They have IPv4 infrastructure, and some of that may not be easily upgradeable.

IPv4 also has a significant advantage in bandwidth overehead.  Deep space links are extremely low bandwidth.  Voyager (admittedly not IP) gets about 160bps.  Mars rovers, when transmitting directly to Earth, get 500bps.  The extra size of IPv6 does make a significant difference at these rates.

Mission planners are going to be pragmatic, not dogmatic. For them, IP is a tool and they will pick the best tool available to meet their mission goals. While we might like them to pick IPv6, their decisions will be based on their mission requirements, and bandwidth is always going to rank high in their decision criteria.

We do not get to dictate to them.  We have no authority over them. The best that we can do is to advocate for our preferred solution. If they choose to use IPv4, and we do not provide addressing infrastructure, then they will simply use legacy prefixes and routing in space will be chaotic.  That is a pragmatic tactical outcome that will have deleterious strategic consequences, which we should avoid.

On the other hand, if we provide addressing infrastructure for both IPv4 and IPv6, we enable sane routing in both the short and long term, regardless of the version selected.

When mission planners are thinking more strategically, working on missions that lead to permanent installations, then the strategic benefits of IPv6 become more apparent, especially in cases where there is higher bandwidth.

Mission planners are going to be the ones evaluating the tradeoffs and making the decision.  We should support them to provide the best pragmatic solution available, regardless of what they choose.

Regards,
Tony