Abstract—iWARP represents the leading edge of high
performance Ethernet technologies. By utilizing an
asynchronous communication model, iWARP brings the
advantages of OS bypass and RDMA technology to Ethernet.
The current specification of iWARP is only defined over
connection-oriented transports such as TCP. The memory
requirements of many connections along with TCP's flow and
reliability controls lead to scalability and performance issues
for large-scale HPC and datacenter applications. In this
research, we propose guidelines to extend iWARP over
datagrams to provide better scalability and performance.
While the proposed extension is designed for use in both HPC
and datacenters, the emphasis of this paper is on HPC
applications. We present our software implementation of
datagram-iWARP over UDP and MPI over datagram-iWARP.
Our microbenchmark and MPI application results show
performance and memory usage benefits for MPI applications,
promoting the use of datagram-iWARP for large-scale HPC
applications.