White pages schema
Encyclopedia
A white pages schema is a data model
, specifically a logical schema
, for organizing the data contained in entries in a directory service
, database, or application, such as an address book. In a white pages directory, each entry typically represents an individual person that makes use of
network resources, such as by receiving email or having an account to log into a system.
In some environments, the schema may also include the representation of organizational divisions, roles, groups, and devices. The term is derived from the white pages, the listing of individuals in a telephone directory
, typically sorted by the individual's home location (e.g. city) and then by
their name.
While many telephone service providers
have for decades published a list of their subscribers in a telephone directory
, and similarly corporations published a list of their employees in an internal directory, it was not until the rise of electronic mail systems that a requirement for standards for the electronic exchange of subscriber information between different systems appeared.
A white pages schema typically defines, for each real-world object being represented:
One of the earliest attempts to standardize a white pages schema for electronic mail use was in X.520 and X.521, part of the X.500
specifications,
that was derived from the addressing requirements of X.400
and defined a Directory Information Tree
that mirrored the international telephone system, with entries representing residential and organizational subscribers. This evolved into the Lightweight Directory Access Protocol
standard schema in RFC 2256. One of the most widely deployed white pages schemas used in LDAP
for representing individuals in an organizational context is inetOrgPerson, defined in RFC 2798, although versions of Active Directory
require a different object class, User. Many large organizations have
also defined their own white pages schemas for their employees or customers, as part of their Identity management
architecture. Converting between data bases and directories using different schemas is often the
function of a Metadirectory
, and data interchange standards such as Common Indexing Protocol
.
Some early directory deployments suffered due to poor design choices in their white pages schema, such as:
Numerous other proposed schemas exist, both as standalone definitions suitable for use with general purpose
directories, or as embedded into network protocols.
Examples of other generic white pages schemas include vCard
, defined in RFC 2426, and FOAF
.
Data model
A data model in software engineering is an abstract model, that documents and organizes the business data for communication between team members and is used as a plan for developing applications, specifically how data is stored and accessed....
, specifically a logical schema
Logical schema
A Logical Schema is a data model of a specific problem domain expressed in terms of a particular data management technology. Without being specific to a particular database management product, it is in terms of either relational tables and columns, object-oriented classes, or XML tags...
, for organizing the data contained in entries in a directory service
Directory service
A directory service is the software system that stores, organizes and provides access to information in a directory. In software engineering, a directory is a map between names and values. It allows the lookup of values given a name, similar to a dictionary...
, database, or application, such as an address book. In a white pages directory, each entry typically represents an individual person that makes use of
User (computing)
A user is an agent, either a human agent or software agent, who uses a computer or network service. A user often has a user account and is identified by a username , screen name , nickname , or handle, which is derived from the identical Citizen's Band radio term.Users are...
network resources, such as by receiving email or having an account to log into a system.
In some environments, the schema may also include the representation of organizational divisions, roles, groups, and devices. The term is derived from the white pages, the listing of individuals in a telephone directory
Telephone directory
A telephone directory is a listing of telephone subscribers in a geographical area or subscribers to services provided by the organization that publishes the directory...
, typically sorted by the individual's home location (e.g. city) and then by
their name.
While many telephone service providers
PTT
PTT may refer to:Chemistry and medicine:* Partial thromboplastin time, a performance indicator in medicine for coagulation status* Photothermal Therapy, A method of using light and photosensitizers for medical treatments...
have for decades published a list of their subscribers in a telephone directory
Telephone directory
A telephone directory is a listing of telephone subscribers in a geographical area or subscribers to services provided by the organization that publishes the directory...
, and similarly corporations published a list of their employees in an internal directory, it was not until the rise of electronic mail systems that a requirement for standards for the electronic exchange of subscriber information between different systems appeared.
A white pages schema typically defines, for each real-world object being represented:
- what attributes of that object are to be represented in the entry for that object
- what relationships of that object to other objects are to be represented
- how is the entry to be named in a DITDirectory Information TreeA directory information tree is data represented in a hierarchical tree-like structure consisting of the Distinguished Names of directory service entries....
- how an entry is to be located by a client searching for it
- how similar entries are to be distinguished
- how are entries to be ordered when displayed in a list
One of the earliest attempts to standardize a white pages schema for electronic mail use was in X.520 and X.521, part of the X.500
X.500
X.500 is a series of computer networking standards covering electronic directory services. The X.500 series was developed by ITU-T, formerly known as CCITT, and first approved in 1988. The directory services were developed in order to support the requirements of X.400 electronic mail exchange and...
specifications,
that was derived from the addressing requirements of X.400
X.400
X.400 is a suite of ITU-T Recommendations that define standards for Data Communication Networks for Message Handling Systems — more commonly known as "email"....
and defined a Directory Information Tree
Directory Information Tree
A directory information tree is data represented in a hierarchical tree-like structure consisting of the Distinguished Names of directory service entries....
that mirrored the international telephone system, with entries representing residential and organizational subscribers. This evolved into the Lightweight Directory Access Protocol
Lightweight Directory Access Protocol
The Lightweight Directory Access Protocol is an application protocol for accessing and maintaining distributed directory information services over an Internet Protocol network...
standard schema in RFC 2256. One of the most widely deployed white pages schemas used in LDAP
for representing individuals in an organizational context is inetOrgPerson, defined in RFC 2798, although versions of Active Directory
Active Directory
Active Directory is a directory service created by Microsoft for Windows domain networks. It is included in most Windows Server operating systems. Server computers on which Active Directory is running are called domain controllers....
require a different object class, User. Many large organizations have
also defined their own white pages schemas for their employees or customers, as part of their Identity management
Identity management
Identity management is a broad administrative area that deals with identifying individuals in a system and controlling access to the resources in that system by placing restrictions on the established identities of the individuals.Identity management is multidisciplinary and covers many...
architecture. Converting between data bases and directories using different schemas is often the
function of a Metadirectory
Metadirectory
A metadirectory system provides for the flow of data between one or more directory services and databases, in order to maintain synchronization of that data, and is an important part of identity management systems. The data being synchronized typically are collections of entries that contain user...
, and data interchange standards such as Common Indexing Protocol
Common Indexing Protocol
The Common Indexing Protocol was an attempt in the IETF working group FIND during the mid-1990s to define a protocol for exchanging index information between directory services....
.
Some early directory deployments suffered due to poor design choices in their white pages schema, such as:
- attributes used for naming purposes were non-unique in large environments (such as a person's common name)
- attributes used for naming purposes were likely to change (such as surnames)
- attributes were included which could lead to Identity theftIdentity theftIdentity theft is a form of stealing another person's identity in which someone pretends to be someone else by assuming that person's identity, typically in order to access resources or obtain credit and other benefits in that person's name...
, such as a Social security numberSocial Security numberIn the United States, a Social Security number is a nine-digit number issued to U.S. citizens, permanent residents, and temporary residents under section 205 of the Social Security Act, codified as . The number is issued to an individual by the Social Security Administration, an independent... - users were required during provisioningProvisioningIn telecommunication, provisioning is the process of preparing and equipping a network to allow it to provide services to its users. In NS/EP telecommunications services, "provisioning" equates to "initiation" and includes altering the state of an existing priority service or capability.In a...
to choose attributes which are unique but still memorable to them
Numerous other proposed schemas exist, both as standalone definitions suitable for use with general purpose
directories, or as embedded into network protocols.
Examples of other generic white pages schemas include vCard
VCard
vCard is a file format standard for electronic business cards. vCards are often attached to e-mail messages, but can be exchanged in other ways, such as on the World Wide Web or Instant Messaging...
, defined in RFC 2426, and FOAF
FOAF (software)
FOAF is a machine-readable ontology describing persons, their activities and their relations to other people and objects. Anyone can use FOAF to describe him or herself...
.