Re: [tcpm] draft-ietf-tcpm-tcp-uto-02

On Fri, Dec 02, 2005 at 08:37:16PM -0800, Fernando Gont wrote:
> 
> >>>/on a satellite/on a non-geostationary satellite/
> >>>- All satellites orbit, but the vast majority used for telecoms take an
> >>>orbit that is goeostationary.
> >>
> >>IIRC, this had been a contribution of (NASA's) Wesley Eddy. "Satellite" 
> >>need not be a communications satellite, but could also be planetary body 
> >>(i.e., a node operating from the Moon experiences periods of 
> >>disconnection)
> >- Yes and is also a rather bizarre illustration of the point, considering 
> >the Path RTT >> "normal Internet MSL" ;-)
> 
> I don't get your point. :-?
>

I don't either.  If the "normal Internet MSL" is 2 minutes, then the
propagation-based RTT between the Earth and Moon of roughly 5.5 seconds
is well within an MSL.

I actually think that changing the text to say "geostationary" would be
an odd example, since from the ground it's rather difficult to go out of
touch with one of these in comparison to other orbits.  The case of a
polar orbit (for instance) where you can predict the amount of time when
the satellite is below the horizon and the time when it'll come back up
is a better example.  In this case, you can use a combination of UTO (to
keep the connection alive) and retransmit-now (to kick the connection),
to gain a little bit of efficiency, and simplify the application by
letting it use TCP in comparison to CFDP or others.

-Wes

-- 
Wesley M. Eddy
Verizon Federal Network Systems
http://roland.grc.nasa.gov/~weddy