[9784] in North American Network Operators' Group
Re: connectivity outside the US
daemon@ATHENA.MIT.EDU (Curtis Generous)
Mon Jun 2 11:06:59 1997
From: Curtis Generous <generous@uucom.com>
To: paul@vix.com (Paul A Vixie)
Date: Mon, 2 Jun 1997 10:39:54 -0400 (EDT)
Cc: nanog@merit.edu
In-Reply-To: <199706012133.OAA24270@wisdom.home.vix.com> from "Paul A Vixie" at Jun 1, 97 02:33:36 pm
According to Paul A Vixie:
>
> > High orbit, geosyncronous sattelites do not stand much of a chance against
> > land lines as the latency on the links is quite high. [...]
>
> Long latency is not automatically bad. It is bad for interactive traffic,
> but if the bandwidth is high enough to reduce congestion to zero, a large
> latency doesn't hurt bulky transfers at all. Netnews, for example, could
> be distributed via satellite without hurting anybody's lookers or feelers.
And with the push to use multicast across such high latency links, you
can get better dessimination of some types of data which involve many
sites within a satellite's foot print (e.g. nntp, ftp mirroring, db
syncronization).
There also is a new proposed spec for doing FTP using multicasting
(MFTP - multicast FTP) which has been tested using some INTELSAT birds
with good results. MFTP has also the characteristic of reduced
sensitivity to long latency, but also to the bit error rate (BER) which
is also a problem when using satellites.
--curtis
--
Curtis Generous generous@uucom.com Phone: (703) 461-1350
UUcom Inc., Suite 250, 4875 Eisenhower Avenue, Alexandria, VA 22304-0797
