<div class="content" name="InitializeSession" uuid="207f7862-b090-4fbc-9a25-e452fcc7e132"><p>This method is called by a client to perform <a href="5fe470fe-8067-470c-a7d7-30553c3dc1f7" data-linktype="relative-path">Catalog Version
Negotiation (section 3.1.4.1)</a>.</p><dl>
<dd>
<div><pre> HRESULT InitializeSession(
   [in] float flVerLower,
   [in] float flVerUpper,
   [in] long reserved,
   [out] float* pflVerSession
 );
</pre></div>
</dd></dl><p><b>flVerLower: </b> The lowest <a href="3f01a312-3391-4109-a96e-95358babf191#gt_0944227d-0566-49e1-989f-2fff6e02542d" data-linktype="relative-path">catalog</a> version supported
by the client. </p><p><b>flVerUpper: </b> The highest catalog version
supported by the client.</p><p><b>reserved: </b> MUST be set to zero when sent and
MUST be ignored on receipt. </p><p><b>pflVerSession: </b>A pointer to a variable that,
upon successful completion, MUST be set to the negotiated catalog version.</p><p><b>Return Values: </b>This method MUST return S_OK
(0x00000000) on success and a failure result, as specified in <a href="../ms-erref/1bc92ddf-b79e-413c-bbaa-99a5281a6c90" data-linktype="relative-path">[MS-ERREF]</a>
section <a href="../ms-erref/0642cb2f-2075-4469-918c-4441e69c548a" data-linktype="relative-path">2.1</a>
on failure. All failure results MUST be treated identically.</p><p>Upon receiving a call to this method, the server MUST verify
that <i>flVerLower</i> is less than or equal to <i>flVerUpper</i>, and fail the
call if not.</p><p>The server then MUST calculate the negotiated catalog
version as the highest catalog version number supported by both the client and
the server, if such a catalog version exists, and store the value as part of
the session state (see section <a href="a667265b-22a8-43bb-b462-13528061e009" data-linktype="relative-path">3.1.1.5</a>). If there is no
catalog version supported by both the client and the server, the server MUST
fail the call.</p><p>The server then MUST set the value referenced by <i>pflVerSession</i>
to the negotiated catalog version and return S_OK (0x00000000).</p></div>