An MPI-2 based parallel-I/O library, Stampi-I/O, has been developed using flexible communication infrastructure. In Stampi-I/O almost all MPI-I/O functions have been implemented. We can execute these functions using both local and remote I/O operations with the same application program interface (API) based on MPI-2. In I/O operations using Stampi-I/O, users need not handle any differences in the communication mechanism of computers. We have evaluated performance for primitive functions in Stampi-I/O. Through this test, sufficient performance has been achieved and effectiveness of our flexible implementation has been confirmed.