A network fabric is a switched interconnect topology, typically non-blocking and multi-path such as a fat-tree or dragonfly, that provides uniform high-bandwidth, low-latency connectivity between many compute nodes. It is the physical and logical substrate over which technologies such as InfiniBand move data between GPUs or servers in a cluster. It underpins distributed training and high-performance computing workloads that depend on collective communication primitives such as the Message Passing Interface.