The ReleaseMapping method informs the application that NAT mapping is no longer required. For example, when a call has completed, the NAT mapping is no longer required. The application should then release the NAT mapping.

HRESULT ReleaseMapping(BSTRbstrInternalLocalAddress,


  • bstrInternalLocalAddress
    [in] Contains the client's internal IP address used during the call.
  • lInternalLocalPort
    [in] Contains the client's internal port used during the call.
  • bstrExternalLocalAddress
    [in] Contains the NAT's external IP address used during the call.
  • lExternalLocalPort
    [in] Contains the NAT's external port used during the call.

Return Values

RTC methods may return any of the standard COM and ADSI return values.


Client: Requires Windows XP SP1.
Server: Requires Windows Server 2003.
Redistributable: Requires Rtcdll.dll on Windows 2000, Windows XP, and Windows Me/98.
Header: Declared in Rtccore.h.
Library: Included as a resource in Rtcdll.dll.
GUID: IID_IRTCPortManager is defined as DA77C14B-6208-43ca-8DDF-5B60A0A69FAC.

See Also

IRTCSessionPortManagement, IRTCPortManager, IRTCPortManager::GetMapping