NdisClGetProtocolVcContextFromTapiCallId function (ndis.h)
NdisClGetProtocolVcContextFromTapiCallId retrieves the client context for a virtual connection (VC) identified by a TAPI Call ID string.
Syntax
NDIS_STATUS NdisClGetProtocolVcContextFromTapiCallId(
[in] UNICODE_STRING TapiCallId,
[out] PNDIS_HANDLE ProtocolVcContext
);
Parameters
[in] TapiCallId
Unicode string that identifies a particular VC. This string is the Unicode version of a string identifier that was previously returned by the NdisCoGetTapiCallID function.
[out] ProtocolVcContext
Pointer to a caller-allocated NDIS_HANDLE that receives a handle to the client context for the VC. The client supplied this context to NDIS on return from its ProtocolCoCreateVc handler.
Return value
Returns one of the following status values:
| Return code | Description |
|---|---|
|
NDIS successfully retrieved the handle to the client VC context for the VC identified by the TAPI Call ID string. |
|
The attempt to retrieve the handle to the client VC context failed. |
Remarks
Suppose a call manager calls NdisCoCreateVc to create a VC for a TAPI call. NDIS in turn supplies the handle to the VC to a client. The client passes this VC handle in a call to the NdisCoGetTapiCallId function to retrieve a string identifier for the VC. The client can then present this identifier as a Unicode string to NdisClGetProtocolVcContextFromTapiCallId to get back its context for the VC.
The client creates a context for each VC that it manages. The client uses NdisCoGetTapiCallId to retrieve a string identifier for each VC. The client passes each string identifier to a TAPI application to identify each VC. Later, if a TAPI application passes one of these string identifiers down to the client in a VC-related operation, the client must pass this string identifier as a Unicode string in a call to NdisClGetProtocolVcContextFromTapiCallId to get back the correct context for the VC.
See the UNICODE_STRING structure for more information.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Supported for NDIS 6.0 and NDIS 5.1 drivers (see NdisClGetProtocolVcContextFromTapiCallId (NDIS 5.1)) in Windows Vista. Supported for NDIS 5.1 drivers (see NdisClGetProtocolVcContextFromTapiCallId (NDIS 5.1)) in Windows XP. |
| Target Platform | Desktop |
| Header | ndis.h (include Ndis.h) |
| Library | Ndis.lib |
| IRQL | DISPATCH_LEVEL |
| DDI compliance rules | Irql_Protocol_Driver_Function(ndis) |