The Dynamic Delegation Discovery System (DDDS) is an algorithm for applying string transformation rules to application-unique strings to extract specific syntax elements. It is used for finding information, such as authoritative domain name servers, for

Uniform Resource Identifier A Uniform Resource Identifier (URI) is a unique sequence of characters that identifies a logical or physical resource used by web technologies. URIs may be used to identify anything, including real-world objects, such as people and places, conc ...

s and

Uniform Resource Name A Uniform Resource Name (URN) is a Uniform Resource Identifier (URI) that uses the scheme. URNs are globally unique persistent identifiers assigned within defined namespaces so they will be available for a long period of time, even after the res ...

s. An earlier specification applied only to URNs, and was called the Resolver Discovery Service (RDS). DDDS defines a mechanism for using the

Domain Name System The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...

(DNS) as the database for arbitrary identifier schemes. The primary logical DNS container used to hold DDDS information is the

NAPTR record A Name Authority Pointer (NAPTR) is a type of resource record in the Domain Name System of the Internet. NAPTR records are most commonly used for applications in Internet telephony, for example, in the mapping of servers and user addresses in the S ...

. DDDS is defined in RFC 3401, RFC 3402, RFC 3403, RFC 3404, and RFC 3405. RFC 3401 expresses the system as follows:RFC 3401, M. Mealling, ''Dynamic Delegation Discovery System (DDDS)'', IETF (October 2002)

The Dynamic Delegation Discovery System is used to implement lazy binding of strings to data, in order to support dynamically configured delegation systems. The DDDS functions by mapping some unique string to data stored within a DDDS Database by iteratively applying string transformation rules until a terminal condition is reached.

Telephone Number Mapping Telephone number mapping is a system of unifying the international telephone number system of the public switched telephone network with the Internet addressing and identification name spaces. Internationally, telephone numbers are systematically ...

(ENUM), specified in RFC 6116, is defined as a DDDS application to resolve telephone numbers into DNS data.

References

Domain Name System {{Compu-network-stub