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From: mckee@MITRE.ARPA.UUCP
Newsgroups: mod.protocols.tcp-ip
Subject: Re: Tcp/Ip vs a store & forward network
Message-ID: <8703301511.AA22345@mitre.ARPA>
Date: Mon, 30-Mar-87 10:11:31 EST
Article-I.D.: mitre.8703301511.AA22345
Posted: Mon Mar 30 10:11:31 1987
Date-Received: Tue, 31-Mar-87 06:15:29 EST
References: <8703300117.AA15165@gwen.cs.purdue.edu>
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You were concerned about the reliability of S&F.  There are a variety of
tradeoffs to consider.  The DoD has an ancient but vigorous system
called AUTODIN.  It has the following characteristics:

    - It is a message switching system; messages are limited to 40,000
characters; each message may have as many as 500 addresses.

    - The "switching" part of the system is fairly small; there are 8
AUTODIN Switching Centers in the US, and a few more in Europe and the
Far East.

    - AUTODIN is EXTREMELY reliable; however, duplicate messages may
occur during recovery from a failure.  The AUTODIN design philosophy is
that it is better to send several messages twice than to drop any
message once.

    - Also, during failure recovery, delivery transposition may occur;
i.e., an older message will be delivered before a newer message.