1. Uniform Resource Names: Deploying A New Namespace Michael Mealling 19 August 1999

2. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Overview of URNs l Meant to be persistent identifiers. Binding to resource is permanent. l Simple identification is useful (XML namespace identification) l A resolution system is available if needed. l Allows for variety in the syntax of the namespace. l Examples: – URN:ISBN:0-07-882396-X – URN:PDI://oma.eop.gov.us/1999/8/5/14.text.2

3. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Deployment Issues l Problem identification l Experimentation l Development l Adoption l Scaling l Management

4. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Problem Identification l We know the general class of problems. Now we need to look at specific ones and apply the proposed solution. – Bibliographic identifies (ISBN, ISSN, DOI) – Schema identification (XML Namespaces) – Document Management (PDI, IETF) – Distributed object systems (Globe)

5. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Experimentation l Once the problems are identified internal use and experimentation begins. – Hidden deployment issues appear. (I.e., the ‘u’ flag issue) – Reusable code begins to appear. – Corporate resource begin to be committed. – We are nearing the end of this phase. Several experiments are ready for “prime time”

6. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Development l Developers begin work on solutions to the problems. Issues to be aware of: – Interoperability – Adherence to the standard. If a large enough segment of the user base does something incorrectly, that incorrect behavior becomes a de facto standard. – Open source software provides a common reference implementation.

7. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Adoption l Moving URNs into the main stream – Must be a compelling reason for either the user or the service provider? – For the user it must be either ‘sexy’ or extremely useful (or at least a functional requirement of something that is). – For the service provider it must be essential for some product that is sellable. – Chicken and egg problem (No one uses it because the software doesn’t support it. The software doesn’t support it because no one uses it.) – Killer app?

8. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Scaling l Scaling of assignment – The IANA is currently the NID authority. Will this scale? l Scaling of resolution – Is a DNS based RDS capable of scaling well enough? l Scaling of actual resolution servers – Is THTTP to simple? – Are other protocols or protocol profiles needed?

9. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Management l To early to tell. If we knew what they would be we could fix them now. l Some possibilities: – Namespace specific knowledge allows for special casing certain URNs which affects interoperability – What happens if we a namespace becomes so popular that it “takes over” the URN space? (I.e. the.com phenomenon happens to URNs)

10. Michael Mealling 19 August 1999 TWIST Meeting University of California, Irvine Current Status l URN Working Group waiting on final documents which are in Last Call. l Namespace registration procedures are being setup now. At least 4 namespaces are in the process of registering. l Software is being released for browsers Real Soon Now ™.