Transport Selection#

oneCCL supports two transports for inter-process communication: Intel® MPI Library and libfabric*.

The transport selection is controlled by CCL_ATL_TRANSPORT.

In case of MPI over libfabric implementation (for example, Intel® MPI Library 2021) or in case of direct libfabric transport, the selection of specific libfabric provider is controlled by the FI_PROVIDER environment variable.