Data centers and HPC clusters often incorporate specialized networking fabrics to satisfy system requirements. However, Ethernet's low cost and high performance are causing a shift from specialized fabrics toward standard Ethernet. Although Ethernet's low-level performance approaches that of specialized fabrics, the features that these fabrics provide such as reliable in-order delivery and flow control are implemented, in the case of Ethernet, by endpoint hardware and software. Unfortunately, current Ethernet endpoints are either slow (commodity NICs with generic TCP/IP stacks) or costly (offload engines). To address these issues, the JNIC project developed a novel Ethernet endpoint. JNIC's hardware and software were specifically designed for the requirements of high-performance communications within future data-centers and compute clusters. The architecture combines capabilities already seen in advanced network architectures with new innovations to create a comprehensive solution for scalable and high-performance Ethernet. We envision a JNIC architecture that is suitable for most in-data-center communication needs.

Computer systems have become powerful enough to process continuous data streams such as video or animated graphics. While processing power and communication bandwidth of today's systems typically are sufficient, quality of service (QoS) guarantees as required for handling such data types cannot be provided by these systems in adequate ways. We present Switcherland, a scalable communication architecture based on crossbar switches that provides QoS guarantees for workstation clusters in the form of reserved bandwidth and bounded transmission delays. Similar to the ATM technology Switcherland provides QoS guarantees with the help of service classes, that is, data transfers are characterized as variable bit rare traffic or constant bit rate traffic. However, unlike LAN technologies, Switcherland is optimized for cluster computing in that (i) it serves as a backplane interconnection fabric as well as a LAN, (ii) it extends support for service classes by also covering the end nodes of the network, (iii) it provides low latency in the order of one microsecond per switch, and (iv) it uses a communication model based on a global memory to simplify programming.