The year of 40 GbE
System architects face many challenges in designing the next generation of ISR systems. They must keep up with the ever increasing amount of sensor data, follow an open systems approach, and make sure that the technology has a future road map. 40 GbE fulfills all of these objectives, making it the logical choice for the next-generation protocol. Ethernet has the most widely supported ecosystem of any protocol, with a clear road map to 100 GbE and beyond. RDMA over 40 GbE means both low latency and low CPU overhead, providing the performance needed for ISR applications.
Optimizing high-performance embedded COTS systems’ design for demanding C4ISR and EW applications such as SIGINT, radar, and image processing will likely always be a balancing act between processing performance and I/O limits. In the commercial market, there tends to be a seesaw effect as one of these factors makes a significant leap forward, followed by the other catching up to help ensure that the available processing or data bandwidth can be fully exploited and to ensure that wasteful system bottlenecks don’t occur. Later this year, the COTS community will experience another such leap forward as we start to see the first products designed for rugged defense and aerospace applications featuring 40 GbE support entering the market.
Double the I/O bandwidth
40 GbE will effectively double the speed of the in-system I/O on embedded COTS systems. In fact, benchmark data now shows that 40 GbE will deliver between 2x and 2.5x the performance of Serial RapidIO Gen 2, consistent with expectations from the increase in speed from 5 Gbaud to 10 Gbaud signaling. And the military market open standards activities are ensuring that the infrastructure is put in place to support the use of 40 GbE in OpenVPX systems. To make sure that the COTS market can take full advantage of the coming performance boost, the VITA community, through its VITA 65 working group, is currently considering multiple new proposals that define OpenVPX profiles for 40 GbE. Customers are already showing interest. Expect to see 40 GbE supported on products from a number of COTS vendors later this year. In fact, Curtiss-Wright plans to announce a number of new products with support for 40 GbE in the near future.
Leveraging HPC protocols
To take full advantage of the performance that 40 GbE offers to new COTS system designs, COTS product designers are leveraging work that has been previously done in the commercial High Performance Computing (HPC) market. HPC system designers commonly use Remote Direct Memory Access (RDMA) to provide memory-to-memory transfers; RDMA reduces latency and processor overhead for various network protocols such as InfiniBand, Serial RapidIO, and Ethernet. The Open Fabrics Alliance’s Open Fabrics Enterprise Distribution (OFED) open source software provides 40 GbE hardware with RDMA capability. OFED provides a device driver layer that largely abstracts RDMA functions, greatly improving data transfers of other higher-level middleware such as MPI and uDAPL. Using OFED can make system integration for HPEC systems, which typically involves heterogeneous hardware and software elements, both simpler and more effective. OFED supports multiple fabrics such as Ethernet, Serial RapidIO, and InfiniBand.
Native Intel support for 40 GbE
Another benefit that 40 GbE brings to new military COTS systems is its native support by Intel Architecture processors. The latest Intel processors feature PCI Express Gen 3 that hooks directly to a 40 GbE NIC, and these processors have Linux driver support for Serial RapidIO, making implementation of 40 GbE much easier. Ethernet also boasts the advantage of familiarity. While 40 GbE will likely find its biggest use as a system backbone in rugged embedded systems, rather than as an end point like GbE, the fact that most users will already be very familiar with the basics of the protocol will provide customers with a high comfort level.
40 GbE benefits COTS community
The move to 40 GbE highlights how the COTS community benefits from its open standards approach. Through the work of standards bodies such as the VSO, military system designers stay well positioned with the processes and flexibility needed to quickly leverage significant technology advances in the commercial world.
Steve Edwards Manager, Product Marketing for ISR Solutions Curtiss-Wright Controls Defense Solutions