Corundum: An Open-Source 100-Gbps NIC

Corundum is an open-source, FPGA-based prototyping platform for network interface development at up to 100 Gbps and beyond. The Corundum platform includes several core features to enable real-time, high-line-rate operations including: a high-performance datapath, 10G/25G/100G Ethernet MACs, PCI Express gen 3, a custom PCIe DMA engine, and native high-precision IEEE 1588 PTP timestamping. A key feature is extensible queue management that can support over 10,000 queues coupled with extensible transmit schedulers, enabling fine-grained hardware control of packet transmission. In conjunction with multiple network interfaces, multiple ports per interface, and per-port event-driven transmit scheduling, these features enable the development of advanced network interfaces, architectures, and protocols. The software interface to these hardware features is a high-performance driver for the Linux networking stack. The platform also supports scatter/gather DMA, checksum offloading, receive flow hashing, and receive-side scaling. Development and debugging is facilitated by a comprehensive open-source, Python-based simulation framework that includes the entire system from a simulation model of the driver and PCI express interface to the Ethernet interfaces. The power and flexibility of Corundum is demonstrated by the implementation of a microsecond-precision time-division multiple access (TDMA) hardware scheduler to enforce a TDMA schedule at 100 Gbps line rate with no CPU overhead.