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request (OSI) (REQ)

  1. Request (REQ) is one of four service primitives defined by the Open Systems Interconnection ( OSI) in the service model between the service user and the service provider. With the service primitive Request, the service user, for example a client, asks the service provider, a provider, for a specific service.
    Service primitives in the OSI reference model

    Service primitives in the OSI reference model

    The requested service provider responds with a response, which the requesting subscriber receives as an acknowledgement from the service provider. Such a query scenario is called a polling service.
  2. The HTTP protocol illustrates the implementation of the service model. In the request-response method used, after the connection is established, the Web browser directs an HTTP request to the Web server, i.e., a request for an HTML document. The server transmits the requested document to the web client in its HTTPresponse. The connection is then terminated again.
  3. In theSNA architecture, a request is a message unit that signals the completion of a particular action or protocol. For example, "Initiate Self" is a request for the activation of an LU-LU session, a session between two Logical Units (LU).
Englisch: request (OSI) - REQ
Updated at: 16.02.2021
#Words: 180
Links: service, open systems interconnection (OSI), service user, service provider (SP), primitive
Translations: DE

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