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OASIS Works to ID Distributed Directory Services

In the pursuit of functional distributed directory services, OASIS Wednesday said it is working to establish a better identification scheme that can be used across domains, applications and transport protocols.

To complete this task, the OASIS Extensible Resource Identifier (XRI) Technical Committee will define a Uniform Resource Identifer (URI), more commonly known as a URL, scheme and a corresponding Uniform Resource (URN) namespace, as well as basic mechanisms for resolving XRIs and exchanging data and metadata associated with XRI resources. Advanced Micro Devices, DataPower, EDS, Novell, Neustar, NRI Pacific, OneName, Visa International and other individuals are spearheading this task.

A fully federated XRI will address the problem of how to identify the same logical resource stored in different physical locations. URIs uniquely identify system resources as specifically attached to a system, such as a Web Server or FTP server. XRI will allow for identifiers to be gauged by both human and computers, and will provide for internationalization in the same manner as XML.

Bill Washburn, president and managing director of the XNS Public Trust Organization (XNSORG), which intends to contribute the Extensible Name Service (XNS) specifications to seed the work of the OASIS committee, explained the need for XRI definition.

"URIs are one of the three pillars of Web architecture, but most URI schemes were developed before the era of XML and Web services," Washburn said.

XRI examined
Jason Bloomberg, analyst for XML and Web services research firm ZapThink, told "You can think of XRI as a system that provides 'URLs for everything' -- data, systems, organizations, services, and people. Currently, we don't have a single, application and protocol-neutral way for identifying these types of resources. What we do have are standards like LDAP, but the XRI initiative goes one big step further and unifies the URL namespaces we know and love from the Web with LDAP and other kinds of directories, as well as other URI-based directory schemes like UDDI."

Fellow ZapThink analyst Ronald Schmelzer discussed the tackling of XRI with

"The XRI idea is a good one, although it really conflicts with many of the initiatives for using URLs within the context of Web Services. For example, much of the purpose of UDDI is to facilitate the dynamic discovery and binding to services that themselves are defined at specific URLs. Thus, the URLs represent a specific binding location and UDDI should be the way to isolate us from having to know those URLs ahead of time -- an automated search engine, to overly simplify things. However, XRI claims that they will be working within the concept of URIs and directory services, such as UDDI. But, the challenge is to get their XRI naming mechanism adopted by those that facilitate creation and deployment of Web Services."

Schmelzer said XRI could face major adoption challenges because Web services superpowers -- Microsoft, IBM, and Sun -- are not behind it yet.

"Sure, things would work better if the universe used XRIs to identify location-independent services, but it will require widespread and consistent implementation. URLs were accepted because they started in an environment where people weren't using an alternate technology for identifying linkable resources. Tim Berners-Lee invented the URL (URI) out of necessity. XRIs now are emerging in an environment where URLs are everywhere. They will need to figure out how to either co-exist or supplant this widespread naming mechanism. My thought is that they will need support of the WS-I as well as the 'heavyweights' IBM, Microsoft, Sun, BEA, and others to make this happen. If you look at the list of participants, I don't see any. This might be an example of a great technology concept with major adoption challenges."