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From: jbn@wdl1.UUCP
Newsgroups: net.unix-wizards
Subject: Re: TCP/IP over T1 query
Message-ID: <347@wdl1.UUCP>
Date: Sat, 23-Mar-85 01:24:21 EST
Article-I.D.: wdl1.347
Posted: Sat Mar 23 01:24:21 1985
Date-Received: Sat, 30-Mar-85 06:13:16 EST
Sender: notes@wdl1.UUCP
Organization: Ford Aerospace, Western Development Laboratories
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Nf-ID: #R:brl-tgr:-937500:wdl1:17100069:000:1072
Nf-From: wdl1!jbn    Mar 22 19:08:00 1985


      The ARPANET is not connected using T1 links.  T1 links run at a
speed of 1.544Mb/sec.  The ARPANET backbone is composed primarily of
56Kb/sec synchronous lines connecting BBN C/30 minicomputers.  End to end,
the ARPANET does not normally deliver more than a fraction of the backbone
rate to any one host. 
      If you are able to solve the hardware problems of interfacing with the
T1 link, there is no reason that it shouldn't work; assuming that you are
running on a VAX, though, the VAX will go compute-bound running the network
software somewhere around 200Kb/sec.  For higher speeds you have to front-end,
with something like the CMC card.  CMC claims that they top out around 1Mb/sec
for a single FTP connection.  But CMC only supports Ethernet at present.
CMC is working on a high-speed intelligent serial card, but it isn't out yet.
      We are doing some work in this area for some military nets; if there
is interest in very high speed network products, please let me know.

					John Nagle
					Ford Aerospace and Communications Corp.
					415-852-4126