struct LPCP_NONPAGED_PORT_QUEUE

typedef struct _LPCP_NONPAGED_PORT_QUEUE
{
     KSEMAPHORE Semaphore;
     PLPCP_PORT_OBJECT BackPointer;
} LPCP_NONPAGED_PORT_QUEUE, *PLPCP_NONPAGED_PORT_QUEUE;

Windows Vista Kernel Structures