Common Name Resolution Protocol (Cnrp)

By Popp, N.

Description
Technical Reference Publication

Excerpt
Introduction: Services are arising that offer a mapping from common names to Internet resources (e.g., as identified by a URI). These services often resolve common name categories such as company names, trade names, or common keywords. Thus, such a resolution service may operate in one or a small number of categories or domains, or may expect the client to limit the resolution scope to a limited number of categories or domains. For example, the phrase Internet Engineering Task Force is a common name in the organization category, as is Moby Dick in the book category. Two classes of clients of such services are being built, browser improvements and web accessible front-end services. Browser enhancements modify the open or address field of a browser so that a common name can be entered instead of a URL. Internet search sites integrate common name resolution services as a complement to search. In both cases, these may be clients of back-end resolution services. In the browser case, the browser must talk to a service that will resolve the common name. The search sites are accessed via a browser. In some cases, the search site may also be the back-end resolution service, but in others, the search site is a front-end to a collection of back-end services.

Table of Contents
Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . 3 2. Important Notes . . . . . . . . . . . . . . . . . . . . . 4 2.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 DTD is Definitive . . . . . . . . . . . . . . . . . . . . 4 2.3 Uniform Resource Identifiers . . . . . . . . . . . . . . . 5 3. Interaction Model . . . . . . . . . . . . . . . . . . . . 5 3.1 Services, Servers, Datasets and Referrals . . . . . . . . 5 3.2 Requests and Responses . . . . . . . . . . . . . . . . . . 5 3.3 Transport Independence . . . . . . . . . . . . . . . . . . 6 3.4 Character encoding . . . . . . . . . . . . . . . . . . . . 6 3.5 Queries . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.6 Hints . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4. Object Model . . . . . . . . . . . . . . . . . . . . . . . 8 4.1 Properties . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1.1 Core properties . . . . . . . . . . . . . . . . . . . . . 8 4.1.2 Abstract and custom properties . . . . . . . . . . . . . . 9 4.1.3 Base properties . . . . . . . . . . . . . . . . . . . . . 9 4.1.4 Common name string encoding and equivalence rules . . . . 11 4.2 Objects . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2.1 Query . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2.1.1 Logical operations within a Query . . . . . . . . . . . . 12 4.2.2 Results . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.2.2.1 ResourceDescriptor . . . . . . . . . . . . . . . . . . . . 13 4.2.3 Service . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.2.3.1 Datasets . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.2.3.2 Servers . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.2.4 Status Messages . . . . . . . . . . . . . . . . . . . . . 19 4.2.4.1 Status of CNRP, Not the Transport . . . . . . . . . . . . 19 4.2.4.2 Codes and Description . . . . . . . . . . . . . . . . . . 19 4.2.4.3 Status Codes . . . . . . . . . . . . . . . . . . . . . . . 19 4.2.5 Referral . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2.5.1 Loop Detection and Dataset Handling in Servers . . . . . . 22 4.2.6 Discoverability: ServiceQuery and Schema . . . . . . . . . 24 5. XML DTD for CNRP . . . . . . . . . . . . . . . . . . . . . 26 6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.1 Service Description Request . . . . . . . . . . . . . . . 28 6.2 Sending A Query and Getting A Response . . . . . . . . . . 29 7. Transport . . . . . . . . . . . . . . . . . . . . . . . . 30 7.1 HTTP Transport . . . . . . . . . . . . . . . . . . . . . . 30 7.2 SMTP Transport . . . . . . . . . . . . . . . . . . . . . . 31 8. Registration: application/cnrp+xml . . . . . . . . . . . . 31 9. Security Considerations . . . . . . . . . . . . . . . . . 32 10. IANA Considerations . . . . . . . . . . . . . . . . . . . 32 References . . . . . . . . . . . . . . . . . . . . . . . . 33