<div class="content" name="NegotiateExtVersion_Line" uuid="5cc40607-c49a-413f-8712-0bd99d6dadd7"><p>The NegotiateExtVersion packet is transmitted from a TAPI <a href="489de77f-16d8-4c4f-939a-f795e8b42893#gt_60e0e1fa-66fe-41e1-b5e3-ceab97e53506" data-linktype="relative-path">client</a> to a TAPI <a href="489de77f-16d8-4c4f-939a-f795e8b42893#gt_434b0234-e970-4e8c-bdfa-e16a30d96703" data-linktype="relative-path">server</a> in a <a href="489de77f-16d8-4c4f-939a-f795e8b42893#gt_8a7f6700-8311-45bc-af10-82e10accd331" data-linktype="relative-path">remote procedure call</a>.
Sending this packet MUST return the highest extension version number that the
service provider can operate under for this device and for the range of
possible extension versions.</p><table>
 <tbody><tr>
  <th><p><br/>0</p></th>
  <th><p><br/>1</p></th>
  <th><p><br/>2</p></th>
  <th><p><br/>3</p></th>
  <th><p><br/>4</p></th>
  <th><p><br/>5</p></th>
  <th><p><br/>6</p></th>
  <th><p><br/>7</p></th>
  <th><p><br/>8</p></th>
  <th><p><br/>9</p></th>
  <th><p>1<br/>0</p></th>
  <th><p><br/>1</p></th>
  <th><p><br/>2</p></th>
  <th><p><br/>3</p></th>
  <th><p><br/>4</p></th>
  <th><p><br/>5</p></th>
  <th><p><br/>6</p></th>
  <th><p><br/>7</p></th>
  <th><p><br/>8</p></th>
  <th><p><br/>9</p></th>
  <th><p>2<br/>0</p></th>
  <th><p><br/>1</p></th>
  <th><p><br/>2</p></th>
  <th><p><br/>3</p></th>
  <th><p><br/>4</p></th>
  <th><p><br/>5</p></th>
  <th><p><br/>6</p></th>
  <th><p><br/>7</p></th>
  <th><p><br/>8</p></th>
  <th><p><br/>9</p></th>
  <th><p>3<br/>0</p></th>
  <th><p><br/>1</p></th>
 </tr>
 <tr>
  <td colspan="32">Req_Func</td>
 </tr>
 <tr>
  <td colspan="32">Reserved1</td>
 </tr>
 <tr>
  <td colspan="32">hLineApp</td>
 </tr>
 <tr>
  <td colspan="32">dwDeviceID</td>
 </tr>
 <tr>
  <td colspan="32">dwTSPIVersion</td>
 </tr>
 <tr>
  <td colspan="32">dwLowVersion</td>
 </tr>
 <tr>
  <td colspan="32">dwHighVersion</td>
 </tr>
 <tr>
  <td colspan="32">lpdwExtVersion</td>
 </tr>
 <tr>
  <td colspan="32">Reserved2</td>
 </tr>
 <tr>
  <td colspan="32">Reserved3</td>
 </tr>
 <tr>
  <td colspan="32">Reserved4</td>
 </tr>
 <tr>
  <td colspan="32">Reserved5</td>
 </tr>
 <tr>
  <td colspan="32">Reserved6</td>
 </tr>
 <tr>
  <td colspan="32">Reserved7</td>
 </tr>
 <tr>
  <td colspan="32">Reserved8</td>
 </tr>
</tbody></table><p><b>Req_Func (4 bytes): </b>An unsigned 32-bit
integer. The identifier of the function that will be invoked on the remote
server. This value MUST be set to 53.</p><dl>
<dd>
<p><b>Return Values</b></p>
</dd>
<dd>
<p>On completion of <a href="c28c36d0-579b-4e20-a100-f4e71012d5f8" data-linktype="relative-path">ClientRequest</a>, this field
contains the result of the encapsulated telephony request. A value of 0
indicates success, and a <a href="e0e8af90-24f1-4dbc-8d4e-01b8e4e7cb53" data-linktype="relative-path">LINEERR_Constants</a>
value indicates failure. The remote server MUST complete this call
synchronously.</p>
</dd>
<dd>
<p>MUST return zero if the function succeeds or an
error number if an error occurs. Common return values are as follows: </p>
</dd>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Name</p>
   </th>
   <th>
   <p>Value</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>LINEERR_INCOMPATIBLEAPIVERSION</td>
  <td>0x8000000C</td>
 </tr><tr>
  <td>LINEERR_OPERATIONUNAVAIL</td>
  <td>0x80000049</td>
 </tr><tr>
  <td>LINEERR_INCOMPATIBLEEXTVERSION</td>
  <td>0x8000000D</td>
 </tr><tr>
  <td>LINEERR_OPERATIONFAILED</td>
  <td>0x80000048</td>
 </tr><tr>
  <td>LINEERR_NODRIVER</td>
  <td>0x80000043</td>
 </tr><tr>
  <td>LINEERR_RESOURCEUNAVAIL</td>
  <td>0x8000004B</td>
 </tr><tr>
  <td>LINEERR_NOMEM</td>
  <td>0x80000044</td>
 </tr></tbody></table>
</dd></dl><p><b>Reserved1 (4 bytes): </b>An unsigned 32-bit
integer. MUST be set to zero when sent and MUST be ignored on receipt. </p><p><b>hLineApp (4 bytes): </b>An <a href="c12b4793-3220-4f9e-aa86-8edd3e7020d4" data-linktype="relative-path">HLINEAPP</a>. The handle to
the client application&#39;s registration with TAPI. This field MUST have been
obtained by sending the <a href="9d8eb7cd-3245-4e44-97e0-42f7b89c9424" data-linktype="relative-path">Initialize</a>
packet.</p><p><b>dwDeviceID (4 bytes): </b>An unsigned 32-bit
integer. Identifies the line device for which interface version negotiation is
performed. A valid value of dwDeviceID is in the range 0 to dwNumDevs –1. The
client obtains dwNumDevs by sending a Initialize packet to the remote server.</p><p><b>dwTSPIVersion (4 bytes): </b>An unsigned 32-bit
integer. The TAPI version number that was negotiated for the specified line
device using NegotiateAPIVersion.</p><p><b>dwLowVersion (4 bytes): </b>An unsigned 32-bit
integer. The lowest extension version number under which TAPI or its client
application can operate. The most-significant WORD is the major version number
and the least-significant WORD is the minor version number. TAPI does not
validate this parameter when this function is called.</p><p><b>dwHighVersion (4 bytes): </b>An unsigned 32-bit
integer. The highest extension version number under which TAPI or its client
application can operate. The most-significant WORD is the major version number
and the least-significant WORD is the minor version number. TAPI does not
validate this parameter when this function is called.</p><p><b>lpdwExtVersion (4 bytes): </b>An unsigned 32-bit
integer. Set to TAPI_NO_DATA (0xFFFFFFFF). Upon successful completion, this
field contains the negotiated extension version number.</p><p><b>Reserved2 (4 bytes): </b>An unsigned 32-bit
integer. This field is used for padding and MUST be ignored on receipt. It can
be any value.</p><p><b>Reserved3 (4 bytes): </b>An unsigned 32-bit
integer. This field is used for padding and MUST be ignored on receipt. It can
be any value.</p><p><b>Reserved4 (4 bytes): </b>An unsigned 32-bit
integer. This field is used for padding and MUST be ignored on receipt. It can
be any value.</p><p><b>Reserved5 (4 bytes): </b>An unsigned 32-bit
integer. This field is used for padding and MUST be ignored on receipt. It can
be any value.</p><p><b>Reserved6 (4 bytes): </b>An unsigned 32-bit
integer. This field is used for padding and MUST be ignored on receipt. It can
be any value.</p><p><b>Reserved7 (4 bytes): </b>An unsigned 32-bit
integer. This field is used for padding and MUST be ignored on receipt. It can
be any value.</p><p><b>Reserved8 (4 bytes): </b>An unsigned 32-bit
integer. This field is used for padding and MUST be ignored on receipt. It can
be any value.</p></div>