Remote Direct Memory Access over the Converged Enhanced Ethernet Fabric: Evaluating the Options

Remote direct memory access (RDMA)-based communication has enjoyed considerable growth since the introduction of the virtual interface architecture (VIA) in the late 1990s. This growth has accelerated since the introduction of the open fabric alliancepsilas (OFA) verbs interface. The stability of this interface and its independence from the underlying physical network has facilitated significant growth of software applications that exploit the benefits of RDMA. Until recently, a user wishing to utilize RDMA could use either the InfiniBand Architecture, which required the use of the unique link and physical layers defined by the InfiniBand Architecture, or the RDDP protocols, designed to run over an IP network. Recent developments in Ethernet have expanded the available options for providing RDMA services to applications while using Ethernet link and physical layers. Specifically, there is a new proposal for adapting the InfiniBand Architecture transport to run over converged enhanced Ethernet (CEE). In this paper we describe this proposal and compare it to two existing methods for delivering RDMA services to an application using existing IP-based transports.