Directory Assistance Service

Directory Assistance Service

The Directory Assistance Service (DAS) is an obsolete protocol and service for accessing X.500 directory services. DAS was intended to provide a lightweight means for clients to access X.500 directory services via a split-Directory User Agent model. Here the Directory User Agent (DUA) (the directory client) is split into a Directory Assistance (DA) client and a Directory Assistant. The directory user would interact with the DA-client, the DA-Client would communicate with the Directory Assistant using the DA protocol, and the Directory Assistant would communicate with the Directory Service using the X.500 Directory Access Protocol (DAP). That is, the Directory Assistant is a Directory Assistance protocol to DAP gateway. This design allows the DA-client to access the directory without requiring it to support the cumbersome Open Systems Interconnection protocol stack.

The Directory Assistance Service was created in 1990 by Marshall T. Rose while at Performance Systems International, Inc., and formally specified in RFC 1202 (published in 1991).

These and related efforts, such as DIXIE, lead to the development of the Lightweight Directory Access Protocol. LDAP replaced the Directory Assistance Service.


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Directory assistance — In telecommunications, directory assistance or directory enquiries is a phone service used to find out a specific telephone number and/or address of a residence, business, or government entity. Contents 1 Technology 2 North America 2.1 Rate… …   Wikipedia

  • Directory Assistance — a telephone company service that furnishes telephone directory information over the telephone. Also called information. * * * …   Universalium

  • Directory Assistance — a telephone company service that furnishes telephone directory information over the telephone. Also called information …   Useful english dictionary

  • directory assistance — di,rectory as sistance noun uncount AMERICAN the service that you phone to find out someone s telephone number: INFORMATION …   Usage of the words and phrases in modern English

  • directory enquiries — diˌrectory enˈquiries , diˌrectory asˈsistance noun [uncountable] the telephone service that provides telephone numbers to people who ask for them; = information AmE * * * directory enquiries UK US noun [U] UK (US directory assistance, US… …   Financial and business terms

  • Assistance dog — An assistance dog is a dog trained to help a person with a disability in daily life. Many are trained by a specific organization, while others are trained by their handler (sometimes with the help of a professional trainer). They are not to be… …   Wikipedia

  • directory enquiries — N UNCOUNT Directory enquiries is a service which you can telephone to find out someone s telephone number. [BRIT] He dialled directory enquiries. (in AM, use information, directory assistance) …   English dictionary

  • directory enquiries — (N. Amer. directory assistance) plural noun a telephone service used to find out someone s telephone number …   English new terms dictionary

  • directory enquiries — BrE directory assistance AmE noun (U) a service on the British telephone network that you can use to find out someone s telephone number …   Longman dictionary of contemporary English

  • Lightweight Directory Access Protocol — The Lightweight Directory Access Protocol (LDAP;  /ˈɛld …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”