<div class="content"><p>The Directory Replication Service (DRS) Remote Protocol is
an <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_8a7f6700-8311-45bc-af10-82e10accd331" data-linktype="relative-path">RPC</a> protocol for <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_a5678f3c-cf60-4b89-b835-16d643d1debb" data-linktype="relative-path">replication</a> and management
of data in <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_e467d927-17bf-49c9-98d1-96ddf61ddd90" data-linktype="relative-path">Active Directory</a>.</p><p>The protocol consists of two RPC interfaces named drsuapi
and dsaop. The name of each drsuapi method begins with &#34;IDL_DRS&#34;,
while the name of each dsaop method begins with &#34;IDL_DSA&#34;. This
protocol was originally implemented in Windows 2000 Server operating system and
is available in all subsequent server releases. It is not available in Windows
NT 3.1 operating system, Windows NT 3.51 operating system, or Windows NT 4.0
operating system.</p><p>Some functionality exposed by these RPC protocols is also
available using the <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_45643bfb-b4c4-432c-a10f-b98790063f8d" data-linktype="relative-path">Lightweight
Directory Access Protocol (LDAP)</a> protocol (<a href="../ms-adts/d2435927-0999-4c62-8c6d-13ba31a52e1a" data-linktype="relative-path">[MS-ADTS]</a>
section <a href="../ms-adts/3c5916a9-f1a0-429d-b937-f8fe672d777c" data-linktype="relative-path">3.1.1.3</a>);
the overlap is described in section <a href="0597aff6-0177-4d52-99f2-14a5441bc3c1" data-linktype="relative-path">1.4</a>.</p><p>The special typographical conventions used in this document
are described in section <a href="d05f9217-c26b-4f64-b16e-2247389319ff" data-linktype="relative-path">3.2</a>.</p><p>State is included in the state model for this specification
only as necessitated by the requirement that a licensee implementation of the
protocols of applicable Windows Server releases has to be capable of receiving
messages and responding in the same manner as applicable Windows Server
releases. Behavior is specified in terms of request message received,
processing based on current state, resulting state transformation, and response
message sent. Unless otherwise specified, all behaviors are required elements
of the protocol. Any specified behavior not explicitly qualified with MAY or
SHOULD is to be treated as if it were specified as a MUST behavior.</p><p><b>AD LDS for Windows Client operating systems</b></p><p>Note that information that is applicable to Active Directory
Lightweight Directory Services (AD LDS) on applicable Windows Server releases
is also generally applicable to AD LDS on Windows clients. For more
information, see [MS-ADTS] section <a href="../ms-adts/bacff5f1-9127-457b-877c-db97b1e1802f" data-linktype="relative-path">1</a>.</p><p><b>Pervasive Concepts</b></p><p>The following concepts are pervasive throughout this
specification.</p><p>This specification uses [KNUTH1] section 2.3.4.2 as a
reference for the graph-related terms <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_c62abd7d-b916-4873-9251-7781d497af27" data-linktype="relative-path">oriented tree</a>, root,
vertex, arc, initial vertex, and final vertex.</p><p><b>replica: </b>A variable containing a set of
objects.</p><p><b>attribute: </b>An identifier for a value or set of
values. See also attribute in the <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb" data-linktype="relative-path">Glossary (section 1.1)</a>.</p><p><b>object: </b>A set of attributes, each with its
associated values. Two attributes of an object have special significance:</p><ul><li><p><span><span> 
</span></span>Identifying attribute: A designated single-valued attribute
appears on every object. The value of this attribute identifies the object. For
the set of objects in a replica, the values of the identifying attribute are
distinct.</p>
</li><li><p><span><span> 
</span></span>Parent-identifying attribute: A designated single-valued
attribute appears on every object. The value of this attribute identifies the <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_8bb43a65-7a8c-4585-a7ed-23044772f8ca" data-linktype="relative-path">object&#39;s</a> parent. That is,
this attribute contains the value of the parent&#39;s identifying attribute or a
reserved value identifying no object (for more information, see [MS-ADTS]
section <a href="../ms-adts/dd4dc725-021b-4c8c-a44a-49b3235836b7" data-linktype="relative-path">3.1.1.1.3</a>).
For the set of objects in a replica, the values of this parent-identifying
attribute define an oriented tree with objects as vertices and child-parent
references as directed arcs, with the child as an arc&#39;s initial vertex and the
parent as an arc&#39;s final vertex.</p>
<p>Note that an object is a value, not a variable; a <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_ea02e669-2dda-460c-9992-b12a23caeeac" data-linktype="relative-path">replica</a> is a variable. The
process of adding, modifying, or deleting an object in a replica replaces the
entire value of the replica with a new value.</p>
<p>As the term &#34;replica&#34; suggests, it is
often the case that two replicas contain &#34;the same objects&#34;. In this
usage, objects in two replicas are considered &#34;the same&#34; if they have
the same value of the identifying attribute and if there is a process in place
(that is, replication) to converge the values of the remaining attributes. When
the members of a set of replicas are considered to be the same, it is common to
say &#34;an object&#34; as a shorthand way of referring to the set of
corresponding objects in the replicas.</p>
</li></ul><p><b>object class: </b>A set of restrictions on the
construction and <a href="e5c2026b-f732-4c9d-9d60-b945c0ab54eb#gt_b242435b-73cc-4c4e-95f0-b2a2ff680493" data-linktype="relative-path">update</a>
of objects. An object class must be specified when an object is created. An
object class specifies a set of must-have attributes (every object of the class
must have at least one value of each) and may-have attributes (every object of
the class may have a value of each). An object class also specifies a set of
possible superiors (the parent object of an object of the class must have one
of these classes). An object class is defined by a <a href="../ms-adsc/6354fe66-74ee-4132-81c6-7d9a9e229070" data-linktype="relative-path">classSchema</a>
object.</p><p><b>parent object: </b>See &#34;object&#34;, above.</p><p><b>child object, children: </b>An object that is not
the root of its oriented tree. The children of an object <i>O</i> is the set of
all objects whose parent is <i>O</i>.</p><p>See [MS-ADTS] section 3.1.1.1.3 for the particular use made
of these definitions in this specification.</p><p>Sections <a href="c3379fc5-123d-4f28-922d-97308561d748" data-linktype="relative-path">1.5</a>,
<a href="9b545b76-247c-44aa-ba77-a3581fa4205a" data-linktype="relative-path">1.8</a>, <a href="063618ed-b2e2-4983-ab13-3ed056700641" data-linktype="relative-path">1.9</a>, <a href="d8a5de32-1b81-441c-b3bc-ce90b1ccd178" data-linktype="relative-path">2</a>, <a href="c56432ff-af88-4443-b500-eecb3047da4d" data-linktype="relative-path">3</a>, <a href="9554afa5-e755-4742-a34b-899fc4e2fd20" data-linktype="relative-path">4</a>, and <a href="c5d90265-1653-4ecc-a0d7-cac691e2d08e" data-linktype="relative-path">5</a> of this specification
are normative. All other sections and examples in this specification are
informative.</p></div>