Resolution of Uniform Resource Identifiers using the Domain Name System (RFC2168)
Original Publication Date: 1997-Jun-01
Included in the Prior Art Database: 2019-Feb-15
Internet Society Requests For Comment (RFCs)
R. Daniel: AUTHOR [+1]
The requirements document for URN resolution systems defines the concept of a "resolver discovery service". This document describes the first, experimental, RDS. It is implemented by a new DNS Resource Record, NAPTR (Naming Authority PoinTeR), that provides rules for mapping parts of URIs to domain names. This memo defines an Experimental Protocol for the Internet community.
Network Working Group R. Daniel Request for Comments: 2168 Los Alamos National Laboratory Category: Experimental M. Mealling Network Solutions, Inc. June 1997
Resolution of Uniform Resource Identifiers using the Domain Name System
Status of this Memo ===================
This memo defines an Experimental Protocol for the Internet community. This memo does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited.
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).
The requirements document for URN resolution systems defines the concept of a "resolver discovery service". This document describes the first, experimental, RDS. It is implemented by 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.
Daniel & Mealling Experimental [Page 1]
RFC 2168 Resolution of URIs Using the DNS June 1997
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.
Uniform Resource Locators have been a significant advance in retrieving Internet-accessible resources. However, their brittle nature over time has been recognized for several years. The Uniform Resource Identifier working group proposed the development of Uniform Resource Names to serve as persistent, location-independent identifiers for Internet resources in order to overcome most of the problems with URLs. RFC-1737  sets forth requirements on URNs.
During the lifetime of the URI-WG, a number of URN proposals were generated. The developers of several of those proposals met in a series of meetings, resulting in a compromi...