<div class="content"><p>The UnHold 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 retrieve the specified held call.</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">
  <p align="center">Req_Func</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved1</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">dwRequestID</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">hCall</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved2</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved3</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved4</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved5</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved6</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved7</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved8</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved9</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved10</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved11</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">Reserved12</p>
  </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 89. </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
MUST contain the result of the encapsulated telephony request. A nonzero
request ID value indicates that the request is in progress and will complete
asynchronously, and a <a href="e0e8af90-24f1-4dbc-8d4e-01b8e4e7cb53" data-linktype="relative-path">LINEERR_Constants</a>
value indicates synchronous failure.</p>
</dd>
<dd>
<p>Returns a positive request identifier if the
function will be completed asynchronously or a negative error number if an
error occurs. The dwParam2 parameter of the corresponding <a href="8f5bc349-fd55-46f2-b0bc-dc9f757317a9" data-linktype="relative-path">LINE_REPLY</a> packet is zero
if the function succeeds, or it is a negative error number if an error occurs.
If the client specified a nonzero value in the dwRequestID field of the packet,
the same value MUST be used for the returned positive request identifier.
Common return values are:</p>
</dd>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Name</p>
   </th>
   <th>
   <p>Value</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>
  <p>LINEERR_INVALCALLHANDLE</p>
  </td>
  <td>
  <p>0x80000018</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_OPERATIONUNAVAIL</p>
  </td>
  <td>
  <p>0x80000049</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_INVALCALLSTATE</p>
  </td>
  <td>
  <p>0x8000001C</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_OPERATIONFAILED</p>
  </td>
  <td>
  <p>0x80000048</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_NOMEM</p>
  </td>
  <td>
  <p>0x80000044</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_RESOURCEUNAVAIL</p>
  </td>
  <td>
  <p>0x8000004B</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_NOTOWNER</p>
  </td>
  <td>
  <p>0x80000046</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_UNINITIALIZED</p>
  </td>
  <td>
  <p>0x80000050</p>
  </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>dwRequestID (4 bytes): </b>An unsigned 32-bit
integer. The identifier of the asynchronous request. </p><dl>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Value</p>
   </th>
   <th>
   <p>Meaning</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>
  <p>0x00000000</p>
  </td>
  <td>
  <p>An unsigned 32-bit integer. The server MUST generate a
  unique positive request ID to return as the Ack_ReturnValue.</p>
  </td>
 </tr><tr>
  <td>
  <p>0x00000001 — 0x7FFFFFFF</p>
  </td>
  <td>
  <p>The server MUST use this value instead of generating a
  unique positive request ID.</p>
  </td>
 </tr></tbody></table>
</dd></dl><p><b>hCall (4 bytes): </b>An <a href="7f4089a0-7432-4ef0-8eeb-5aafe407c07e" data-linktype="relative-path">HCALL</a>. The handle to the
call to be retrieved. The application MUST be an owner of this call. The call
state of hCall must be onHold, onHoldPendingTransfer, or
onHoldPendingConference. This handle can be obtained by sending the <a href="c00d4831-5c37-4ee7-99a5-2e18c6cc3d1e" data-linktype="relative-path">Hold</a> packet to the remote
server.</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><p><b>Reserved9 (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>Reserved10 (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>Reserved11 (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>Reserved12 (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>