NdisClGetProtocolVcContextFromTapiCallId (NDIS 5.1) function

Article
06/19/2017

Note NDIS 5. x has been deprecated and is superseded by NDIS 6. x. For new NDIS driver development, see Network Drivers Starting with Windows Vista. For information about porting NDIS 5. x drivers to NDIS 6. x, see Porting NDIS 5.x Drivers to NDIS 6.0.

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

TapiCallId [in]
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.
ProtocolVcContext [out]
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_STATUS_SUCCESS	NDIS successfully retrieved the handle to the client VC context for the VC identified by the TAPI Call ID string.
NDIS_STATUS_FAILURE	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

Target platform	Universal
Version	See NdisClGetProtocolVcContextFromTapiCallId.
Header	Ndis.h (include Ndis.h)
Library	Ndis.lib
IRQL	DISPATCH_LEVEL

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