1.3 Overview

The WS-Enumeration [WSENUM] and WS-Transfer [WXFR] specifications are SOAP-based protocols that define various operations to manage data on a server. The WSPELD Protocol specifies LDAP v3 control extensions to operations defined by these protocols when the service implementation is targeting a LDAP v3 directory server [RFC2251].

Section 4.1.12 of [RFC2251] specifies that a client can send a control to the directory server by attaching a control structure to an LDAP operation.

A control consists of the following:

  • An object identifier (OID) assigned to the control.

  • The criticality value (true or false).

  • The controlValue contents.

A control sent by the client to a server is known as a request control. In some cases, the server includes a corresponding control structure attached to the response for the LDAP operation. These controls are known as response controls.

The control structures are used for extending existing LDAP operations. For instance, a directory server based on LDAP v3 [RFC2251] might enforce the limits to the maximum number of objects (maxLimit) that can be returned in a single search operation performed. If the server enforces the maxLimit, then the pagedResultsControl control documented in [RFC2696] can be used to perform searches that return more objects than maxLimit by splitting the search into multiple searches, each of which returns no more objects than maxLimit. The pagedResultsControl control can be used as both a request control and response control.

WSPELD provides a way of sending and receiving the LDAP v3 controls explained here to control the operations defined by the WS-Enumeration and WS-Transfer protocols in a specific manner depending on the nature of the control [RFC2251]. These LDAP v3 control extensions apply to both request and response SOAP messages.