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From: deering@PESCADERO.STANFORD.EDU (Steve Deering)
Newsgroups: comp.archives
Subject: [tcp-ip] Re: What is VMTP?
Message-ID: <1990May31.161251.2133@math.lsa.umich.edu>
Date: 31 May 90 16:12:51 GMT
Sender: emv@math.lsa.umich.edu (Edward Vielmetti)
Reply-To: deering@PESCADERO.STANFORD.EDU (Steve Deering)
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Archive-name: vmtp/31-May-90
Original-posting-by: deering@PESCADERO.STANFORD.EDU (Steve Deering)
Original-subject: Re: What is VMTP?
Archive-site: gregorio.stanford.edu [36.8.0.11]
Archive-directory: vmtp-ip
Reposted-by: emv@math.lsa.umich.edu (Edward Vielmetti)

> I've read bits & pieces about something called VMTP.  From what I've seen,
> it appears to be a reliable counterpart of UDP.
> Can someone explain in more depth exactly what VMTP is and/or provide
> easily available references?

VMTP is a transport-layer protocol that provides a reliable request/response
or RPC style of service, rather than the reliable stream service of TCP or
the unreliable datagram service of UDP.  As others have pointed out, it
has been described in several papers by David Cheriton of Stanford; the
protocol specification can be found in RFC-1045.

> Are there any implementations under UNIX?

Yes, there is an implementation for 4.3BSD and derivitives (SunOS, Ultrix)
that may be obtained by anonymous FTP from host gregorio.stanford.edu,
in the vmtp-ip directory.  The software is free but covered by a
Stanford license agreement, which can be found in the file vmtp.LICENSE
in that directory.

Steve Deering