Communication Protocols

It is important to specify the communication protocol used by a parallel program.  This affects the software and hardware used for communication and has ramifications for performance.  The means by which this is accomplished for MPI is through the variable  MPI_COMM.  This must be set prior to calling vsched -m.  The settings are case sensitive.

            set MPI_COMM=TCP

TCP runs over ethernet and is available on all clusters. It is currently the only communication protocol available on this system.