An extranet is a controlled private network that allows access to partners, vendors and suppliers or an authorized set of customers – normally to a subset of the information accessible from an organization's
intranet An intranet is a computer network A computer network is a group of computers that use a set of common communication protocols over digital signal, digital interconnections for the purpose of sharing resources located on or provided by the No ...

. An extranet is similar to a DMZ in that it provides access to needed services for authorized parties, without granting access to an organization's entire network. Historically, the term was occasionally also used in the sense of two organizations sharing their internal networks over a
virtual private network The term virtual private network (abbreviated VPN) describes any technology that can encapsulate and transmit network data, typically Internet Protocol data, over another network. Such a system enables users to access network resources that may ...

Enterprise applications

During the late 1990s and early 2000s, several industries started to use the term 'extranet' to describe centralized repositories of shared data (and supporting applications) made accessible via the web only to authorized members of particular work groups - for example, geographically dispersed, multi-company project teams. Some applications are offered on a
software as a service Software as a service (SaaS ) is a software licensing and software delivery, delivery model in which software is licensed on a subscription basis and is centrally Internet hosting service, hosted. It is sometimes referred to as "on-demand software" ...
(SaaS) basis. For example, in the construction industry, project teams may access a project extranet to share drawings, photographs and documents, and use online applications to mark-up and make comments and to manage and report on project-related communications. In 2003 in the
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain,Usage is mixed. The Guardian' and Telegraph' use Britain as a synonym for the United Kingdom. Some prefer to use Britain as shortha ...

United Kingdom
, several of the leading vendors formed the Network for
Construction Collaboration TechnologyConstruction collaboration technology refers to software applications used to enable effective sharing of project-related information between geographically dispersed members of a construction Construction is a general term meaning the art and ...
Providers (NCCTP) to promote the technologies and to establish data exchange standards between the different data systems. The same type of construction-focused technologies have also been developed in the United States, Australia and mainland Europe.


* Exchange large volumes of data using Electronic Data Interchange (EDI) * Share product catalogs exclusively with trade partners * Collaborate with other companies on joint development efforts * Jointly develop and use training programs with other companies * Provide or access services provided by one company to a group of other companies, such as an online banking application managed by one company on behalf of affiliated banks *improved efficiency: since the customers are satisfied with the information provided it can be an advantage for the organization where they will get more customers which increases the efficiency.


* Extranets can be expensive to implement and maintain within an organization (e.g., hardware, software, employee training costs), if hosted internally rather than by an application service provider. * Security of extranets can be a concern when hosting valuable or proprietary information.

See also

*LAN *List of collaborative software *Wide area network


Further reading

* Callaghan, J. (2002), ''Inside Intranets & Extranets: Knowledge Management and the Struggle for Power'', Palgrave Macmillan, *Stambro, Robert and Svartbo, Erik (2002),
Extranet Use in Supply Chain Management
', University of Technology * {{Authority control Computer network security Network architecture