RFC 1729 (rfc1729) - Page 1 of 8
Using the Z39
Alternative Format: Original Text Document
Network Working Group C. Lynch
Request for Comments: 1729 University of California
Category: Informational Office of the President
December 1994
Using the Z39.50 Information Retrieval Protocol
in the Internet Environment
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Summary
This memo describes an approach to the implementation of the
ANSI/NISO Z39.50-1992 Standard for Information Retrieval in the
TCP/IP environment which is currently in wide use by the Z39.50
implementor community.
Introduction
Z39.50 is a US national standard defining a protocol for computer-
to-computer information retrieval that was first adopted in 1988 [1]
and extensively revised in 1992 [2]. It was developed by the National
Information Standards Organization (NISO), an ANSI-accredited
standards development body that serves the publishing, library, and
information services communities. The closely related international
standard, ISO 10162 (service definition) [3] and 10163 (protocol)
[4], colloquially known as Search and Retrieve or SR, reached full
International Standard (IS) status in 1991. Work is ongoing within
ISO Technical Committee 46 Working Group 4 Subgroup 4 to progress
various extensions to SR through the international standards process.
The international standard is essentially a compatible subset of the
current US Z39.50-1992 standard. Z39.50 is an applications layer
protocol within the OSI reference model, which assumes the presence
of lower-level OSI services (in particular, the presentation layer
[5]) and of the OSI Association Control Service Element (ACSE) [6]
within the application layer.
Many institutions implementing this protocol chose, for various
reasons, to layer the protocol directly over TCP/IP rather than to
implement it in an OSI environment or to use the existing techniques
that provide full OSI services at and above the OSI Transport layer
on top of TCP connections (as defined in RFC 1006 [7] and
implemented, for example, in the ISO Development Environment
Lynch
