The GetCallInstanceDataLength API is used when an application is receiving call instance data with a phone call. This API procedure is used by the receiving end of a call to obtain the number of bytes in the call's instance data. Call instance data can be ASCII or raw binary data and its format is dictated by the application. Call instance data that is part of a phone call can be used for whatever reasons the application requires.

Generally you would call this procedure when the event callback sends you the SipIncomingCallStart or the SipTransferExecuting event indication.

Namespace:  LanScape
Assembly:  LMEVoipManaged (in LMEVoipManaged.dll) Version: 6.0.5226.26700


public VoipMediaEngine..::.TELEPHONY_RETURN_VALUE GetCallInstanceDataLength(
	int PhoneLine,
	ref int UserCallInstanceLength
Visual Basic (Declaration)
Public Function GetCallInstanceDataLength ( _
	PhoneLine As Integer, _
	ByRef UserCallInstanceLength As Integer _
Visual C++
VoipMediaEngine..::.TELEPHONY_RETURN_VALUE GetCallInstanceDataLength(
	int PhoneLine, 
	int% UserCallInstanceLength
public VoipMediaEngine..::.TELEPHONY_RETURN_VALUE GetCallInstanceDataLength(
	int PhoneLine,
	/** @ref */int UserCallInstanceLength


Type: System..::.Int32
The zero based phone line to access.
Type: System..::.Int32 %
A reference to the return value that will indicate how many bytes of call instance data exist for the call.

Return Value

If the function succeeds, the return value will be SipSuccess.

If the function fails, the return value will be one of the following values as specified by the VoipMediaEngine..::.TELEPHONY_RETURN_VALUE data type.

Return ValueDescription
This value is returned by telephony API procedures to indicate general API failure. This error value is used as a "catch all error". If you receive this error, check to make sure that all parameters specified in the API procedure call are correct. Particularly, verify that pointers to memory regions are valid. This error return value is only used if a mapping to another specific error value does not exist.

(API return value)

One of the telephony API procedures was called by application software and was passed a pointer to an invalid memory address. Normally this error will occur when application software passes NULL pointer values to the telephony API. For managed code applications, you should never see this error unless your process space has exhausted memory.

(API return value)

Application software specified an invalid telephony handle in one of the API procedures. This usually indicates memory corruption on the part of application software.

(API return value)

Application software called a telephony API procedure and specified an invalid phone line. Phone lines are numbered starting from zero. This error is most commonly returned when attempting to access phone lines in excess of the max number of lines supported by the telephony engine.

(API return value)

An application will receive this API return value when it calls the GetCallInstanceData(Int32, array<Byte>[]()[]) API procedure and when there is no call instance data associated with the phone call.

(API return value)



See Also