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), formerly Universal Resource Identifier, is a unique sequence of characters that identifies an abstract or physical resource, such as resources on a webpage, mail address, phone number, books, real-world obje ...

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 re ...

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 name service that provides a naming system for computers, services, and other resources on the Internet or other Internet Protocol (IP) networks. It associates various information ...

(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 expresses the system as follows:

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 (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