[Starlink] IXPs in space

[David Fernández]

Apologies in advance for any *profound* misunderstanding that could
trigger any nerves, although I am grateful for all the info being
shared. I will read this carefully:
https://web.mit.edu/Saltzer/www/publications/endtoend/endtoend.pdf

In the abstract, I read, at the end: "Low level mechanisms to support
these functions are justified only as performance enhancements." So,
every rule has its exceptions, like the PEPs for TCP performance
acceleration.

"Adding those anycast addresses to the satellites would be transparent
to all users (assuming the satellites are operating at the IP layer,
the old bent-pipe approach did not, but once you have routing in space
via the laser links...)" Satellites being routers just because they
have ISL does not follow. Is there any satellite nowadays doing
routing in space? They do switching only (and not Ethernet switching).
Because of this I proposed the idea of the so called L2 snooping. It
is a hack, somehow similar to the PEPs to accelerate TCP, but in this
case to accelerate DNS (not encrypted), without making satellites
routers, keeping them transparent as they are now.

If it has not been done before by anybody is for a good reason, maybe.
Things like this did not have so much success, it seems:
https://en.wikipedia.org/wiki/Internet_Routing_in_Space

"DNS is an easy thing to start with compared to most others." Even in
this case you are going to find a lot of issues to do it with
transparent satellites, even with GEO satellites, where the gain could
be bigger and things simpler than with fast moving LEO satellites.

"bent pipe for normal operations doesn't mean that you can't watch for
an anycast address to serve locally." This is what I was suggesting,
you sniff packets in the satellite uplink and answer anycast DNS
queries directly from satellite, if you see any, cutting RTT by a
half.

Regards,

David