<div class="content"><p>The AgentSpecific 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 allows the application to access proprietary
handler-specific functions of the agent handler that is associated with the
address. </p><p>The meaning of the extensions are specific to the agent
handler. Each set of agent-related extensions is identified by a universally
unique 128-bit extension ID that MUST be obtained, along with the specification
for the extension, from the promulgator of that extension (usually the author
of the agent handler software on the telephony server). </p><p>The list of extensions that are supported by the agent
handler is obtained from the <a href="038bbda5-b88d-43d0-965e-983579f9ed7e" data-linktype="relative-path">LINEAGENTCAPS</a>
packet that is returned by the <a href="5f15fc21-d90b-44d1-bf0e-20248ec2dd88" data-linktype="relative-path">GetAgentCaps</a> packet.</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">lpContext</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">hLine</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">dwAddressID</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">dwAgentExtensionIDIndex</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">lpParamsContext</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">lpParams</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">dwSize</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">VarData
  (variable)</p>
  </td>
 </tr>
 <tr>
  <td colspan="32">
  <p align="center">...</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 6. </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 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. If the client specified a nonzero value in the dwRequestID field
of the packet, the same MUST be used as the value for the returned positive
request identifier. </p>
</dd>
<dd>
<p>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>
  <p>LINEERR_INVALADDRESSID</p>
  </td>
  <td>
  <p>0x80000011</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_INVALAGENTID</p>
  </td>
  <td>
  <p>0x80000057</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_INVALLINEHANDLE</p>
  </td>
  <td>
  <p>0x8000002B</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_INVALPARAM</p>
  </td>
  <td>
  <p>0x80000032</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_INVALPOINTER</p>
  </td>
  <td>
  <p>0x80000035</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_NOMEM</p>
  </td>
  <td>
  <p>0x80000044</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_OPERATIONFAILED</p>
  </td>
  <td>
  <p>0x80000048</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_OPERATIONUNAVAIL</p>
  </td>
  <td>
  <p>0x80000049</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_RESOURCEUNAVAIL</p>
  </td>
  <td>
  <p>0x8000004B</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_STRUCTURETOOSMALL</p>
  </td>
  <td>
  <p>0x8000004D</p>
  </td>
 </tr><tr>
  <td>
  <p>LINEERR_UNINITIALIZED</p>
  </td>
  <td>
  <p>0x80000050</p>
  </td>
 </tr></tbody></table>
</dd>
<dd>
<p>Additional return values are
specific to the agent handler.</p>
</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>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>lpContext (4 bytes): </b>An unsigned 32-bit
integer. The opaque, client-specified value that is used by the client upon
request completion; MUST be returned by the server in the request completion
packet.</p><p><b>hLine (4 bytes): </b>An <a href="9a80ee5c-cf55-4a86-bd67-173059d6ff3c" data-linktype="relative-path">HLINE</a>. The handle to the
open line device. This field MUST have been obtained by sending the <a href="2759c744-e040-4c5d-b4b5-215d391f0490" data-linktype="relative-path">Open</a> packet.</p><p><b>dwAddressID (4 bytes): </b>An unsigned 32-bit
integer. The address on the open line device. An address identifier is
permanently associated with an address; the identifier remains constant across
operating system upgrades. A valid value of dwAddressID is in the range 0 to
dwNumAddresses –1. The client obtains dwNumAddresses from the <a href="f236ea7a-c8a2-4681-b87c-9f0e07a01dc6" data-linktype="relative-path">LINEDEVCAPS</a> obtained by
sending a <a href="ee317c21-100e-48a3-bcce-e9991efff889" data-linktype="relative-path">GetDevCaps</a>
packet to the remote server.</p><p><b>dwAgentExtensionIDIndex (4 bytes): </b>An unsigned
32-bit integer. The position in the ExtensionIDList packet in LINEAGENTCAPS of
the agent handler extension being invoked. A valid value of
dwAgentExtensionIDIndex is in the range 0 to dwNumAgentExtensionIDs – 1. The
client obtains dwNumAgentExtensionIDs from the LINEAGENTCAPS obtained by
sending a GetAgentCaps packet to the remote server.</p><p><b>lpParamsContext (4 bytes): </b>An unsigned 32-bit
integer. The opaque, client-specified value that is used by the client upon
request completion; MUST be returned by the server in the request completion
packet.</p><p><b>lpParams (4 bytes): </b>An unsigned 32-bit
integer. The offset, in bytes, in the VarData field of a parameter block. The
format of this parameter block is device specific and its contents are passed
by TAPI to and from the agent handler application on the telephony server. This
parameter block MUST specify the function to invoke and include sufficient room
for data to be returned.</p><p><b>dwSize (4 bytes): </b>An unsigned 32-bit integer.
The size, in bytes, of the parameter block that is indicated in the lpParams
field.</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>VarData (variable): </b>Contains a parameter block
that corresponds to the proprietary handler-specific functions of the agent
handler. This data is opaque to the protocol.</p><dl>
<dd>
<p>The contents of this field MUST be DWORD-aligned, as
specified in <a href="../ms-dtyp/cca27429-5689-4a16-b2b4-9325d93e4ba2" data-linktype="relative-path">[MS-DTYP]</a>
section <a href="../ms-dtyp/262627d8-3418-4627-9218-4ffe110850b2" data-linktype="relative-path">2.2.9</a>.</p>
</dd></dl></div>