From mboxrd@z Thu Jan  1 00:00:00 1970
From: presotto@plan9.bell-labs.com
To: 9fans@cse.psu.edu
Subject: Re: [9fans] rudp
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Date: Sun,  9 Sep 2001 21:46:04 -0400
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An rudp channel really is a datagram channel.  Packets are
separately addressed by the user program so that one fd
can be used to maintain conversations with multiple other
end points.  IL is one to one.

IL does have flow control, Rudp doesn't.

Rudp has no keep alive, IL does.

IL does some small amount of congestion control by measuring the
bandwidth delay product of the connection, Rudp doesn't care.

Rudp connections don't hangup when one of the sides reboots, it
just flushes any undelievered messages to that side (and the side(s)
that stays up can know that there was a restart by looking at the error
file).

We used rudp as the protocol between things like controllers
and devices that they control.  For example, between a switch
and a switch controller in a telephony product.

Rudp is just udp with a some extra bytes.  It was originally
done as an option on udp and we later just made it a
separate protocol.  It's protocol number is not registered
witn IANA.