[OpenAFS-devel] dcerpc.net - freedce

[Jeffrey Hutzelman]

On Mon, 13 Aug 2001, Marcus Watts wrote:

> Andrew File System was originally developed at CMU in partnership with
> IBM.  It was then spun off into a separate organization, transarc.
> Around 1990, transarc was selling AFS 3.1.  This was (just like current
> AFS 3 based releases includeing openafs) based on RX, which is actually
> not entirely its own creation but heavily based on SUN RPC.  There
> are traces of support for an older protocol ("r"?) in some parts
> of AFS 3, which probably predate AFS 3.  I think I once saw some
> documentation for some of the AFS 2 utilities which ran under RT/AOS 3.

About the only thing Rx has in common with sunrpc is XDR, which is pretty
much identical in both protocols (enough so that kernel-rx does not
include its own XDR, but instead depends on the one already present in the
kernel for supporting NFS).

The older RPC protocol was indeed called 'R'.  There are a few ancient
Andrew tools that still use R, but it's basically unauthenticated and not
useful for much.

> DCE RPC uses ASN.1, which is definitely less efficient at storing data

That's not fair.  ASN.1 has a number of distinct advantages over XDR,
particularly when you are trying to design an extensible protocol or use
datatypes that don't fit neatly into the usual native ones.  And it can be
quite efficient, depending on what encoding rules you use.  Of course,
you're right about people mis-implementing it left and right.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+@cmu.edu>
   Sr. Research Systems Programmer
   School of Computer Science - Research Computing Facility
   Carnegie Mellon University - Pittsburgh, PA