[1717] in Commercialization & Privatization of the Internet
re: What constitutes high speed networking?
daemon@ATHENA.MIT.EDU (Craig Partridge)
Fri Dec 13 12:17:35 1991
To: CK.MAN@rxg.xerox.com
Cc: com-priv@psi.com
Date: Fri, 13 Dec 91 09:10:40 -0800
From: Craig Partridge <craig@aland.bbn.com>
Regarding your request for definitions -- I've publicly said that the
proper definition of an N-bits/s network is that there exists a path,
all the way to the user's machine that could conceivably transmit/receive
at N-bits/s. (I say "conceivably", because in almost every architecture,
at some point, some sharing may occur, which may give the user somewhat
less bandwidth; e.g. a shared Ethernet in the middle of a business day won't
give you 10Mbits/second, but it often will give you 10Mbits/s early or
late in the day [OK 8.9Mbits/second after accounting for headers :-)]).
I've pushed this view because I've heard some folks refer to their test
networks as terabit networks, because the aggregate capacity of the network
is measured in terabits, when you sum all the paths. But no individual
computer gets access to a link with anywhere close to that speed.
And as for "INEXPENSIVELY priced, RELIABLE data comms" of at least 56Kbit,
it isn't as hard as your note makes it sound. The real question is the
cost structure of the PTT providing service. For example, I've been
engaged in pricing leased lines and dialup line costs for several networks.
I know of cases in which a 56Kbit leased-line over a modest distance into one's
corporate network is about comparable in cost to buying 9600-baud dial-up
service offered by some of the commercial providers. (Yes there are some
funny economics here, but even after you adjust for them, 56Kbit is awfully
close in cost). On an even wilder note, gigabit-ready single-mode fiber is
available in Boston and adjacent towns for about the same price as a leased
T1. More pragmatically, I've been told that NTT plans to have 56Kbit ISDN t
o all homes in Japan by sometime in the mid-1990s and very low-cost 56Kbit
service is available (I'm told -- I wasn't able to get it myself) within
parts of the Bay Area.
Craig
