Remote Direct Memory Access (RDMA) provides a low latency, high throughput network interconnect with kernel bypass and zero copy between application virtual memory regions. RDMA deployments require expensive, specialized hardware. Software RDMA providers have been developed to allow testing and research of RDMA features without this specialized hardware. Historically, these software providers, including softiwarp and softroce (rxe), have been implemented in the kernel. Using DPDK, we have developed an RDMA provider named urdma that performs data transfer entirely in userspace with only minimal connection management in the kernel. The urdma provider uses a variant of the standard iWARP protocol over UDP, and is capable of running on commodity NICs. The kernel and userspace components of urdma are available under an open-source license. This presentation will discuss goals, the design and implementation of the provider, issues encountered during development, and a performance evaluation.
