from nx_ipv4.h:162
UINT _nx_ip_header_add(NX_IP *ip_ptr,
NX_PACKET *packet_ptr,
ULONG source_ip,
ULONG destination_ip,
ULONG type_of_service,
ULONG time_to_live,
ULONG protocol,
ULONG fragment);
Implemented in nx_ip_header_add.c:88