Subject: I-D Action:draft-keiser-afs3-xdr-union-01.txt

From: [email-masked]
Date: Mon, 25 Apr 2011 07:15:02 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title           : Extensible XDR Discriminated Union Primitive Type
	Author(s)       : T. Keiser
	Filename        : draft-keiser-afs3-xdr-union-01.txt
	Pages           : 10
	Date            : 2011-04-25

AFS-3 relies upon XDR to carry Rx RPC call payloads.  XDR
discriminated unions are ill-suited to cases where the protocol needs
to evolve without inventing new RPCs, i.e., unknown discriminant
values cause the entire XDR payload to fail the decoding step.  While
this can be circumvented through the use of opaque payloads (and
recursive XDR invocations), such solutions are inelegant and
difficult to implement.  This memo defines a new XDR primitive type,
"ext-union", which is derived from the XDR discriminated union
primitive type, but with two key variations: 1) each leg contains a
length field, and 2) no default leg is supported.

Internet Draft Comments

Comments regarding this draft are solicited.  Please include the
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