Resolution of Uniform Resource Identifiers using the Domain Name System

Status of this Memo =================== This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ''work in progress.'' To learn the current status of any Internet-Draft, please check the ''1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), Abstract: ========= Uniform Resource Locators (URLs) are the foundation of the World Wide Web, and are a vital Internet technology. However, they have proven to be brittle in practice. The basic problem is that URLs typically identify a particular path to a file on a particular host. There is no graceful way of changing the path or host once the URL has been assigned. Neither is there a graceful way of replicating the resource located by the URL to achieve better network utilization and/or fault tolerance. Uniform Resource Names (URNs) have been hypothesized as a adjunct to URLs that would overcome such problems. URNs and URLs are both instances of a broader class of identifiers known as Uniform Resource Identifiers (URIs). This document describes a new DNS Resource Record, NAPTR (Naming Authority PoinTeR), that provides rules for mapping parts of URIs to domain names. By changing the mapping rules, we can change the host that is contacted to resolve a URI. This will allow a more graceful handling of URLs over long time periods, and forms the foundation for a new proposal for Uniform Resource Names. In addition to locating resolvers, the NAPTR provides for other naming systems to be grandfathered into the URN world, provides independence between the name assignment system and the resolution protocol system, and allows multiple services (Name to Location, Name to Description, Name to Resource, ...) to be offered. In conjunction with the SRV RR, the NAPTR record allows those services to be replicated for the purposes of fault tolerance and load balancing.