This suite investigates the functions available for all or for a given RPC interface by making call requests for all opnums 0 to 500 and checking the fault code or status code.
When the opnum is out of range, Windows returns DCERPC_NCA_S_OP_RNG_ERROR as the RPC fault code (in the Response PDU/pkt), which is converted to the status code NT_STATUS_NET_WRITE_FAULT, which is not one of the status codes that the test considers 'passing'.
It looks like almost all fault codes cause Samba to produce NT_STATUS_NET_WRITE_FAULT.
This test, in addition to checking the status code as it does now, should (1) also check the underlying fault code, as that will help investigation and then (2) should check for the fault code DCERPC_NCA_S_OP_RNG_ERROR and consider that as 'passing' the test for that RPC interface.
DCERPC_NCA_S_OP_RNG_ERROR is, according to my understanding of [DCE/RPC 1.1], the correct code for an RPC server to return in this case.
If this bug is fixed, along with #7851 and #7845, this suite will pass against Windows(any version).