Until recently, most high-availability systems were "hand-rolled" with proprietary architectures. The Advanced Tele - com Computing Architecture (ATCA) and MicroTCA specifications from the PICMG organization, collectively known as xTCA, have changed this regime. The xTCA platforms provide a systematic approach to building standard, reliable, modular, network-centric systems with multi-vendor support. xTCA features include redundancy, cooling, fault isolation, ESD protection, rapid MTTR, and advanced system management.

The xTCA specifications were developed and fine-tuned to provide availability as high as 99.999%. This is equivalent to an average system downtime of less than 5.26 minutes each year, using standard commercial off-the-shelf enclosures and boards! For the first time in embedded system engineering, there is a costeffective, standard commercial approach to building high-availability systems.

The Network Rules

Figure 2. Fourteen-slot ATCA undersea enclosure with conductively cooled power units.
Not only does xTCA provide superb availability, it also provides an excellent open network-centric platform for modern systems. All xTCA blade slots have network connectivity with standard 1000BASE-TX dual-redundant Ethernet links to each card slot for a "base" dual-star network. In addition to the base network, the system engineer can select a platform with 1 and/or 10 Gbps high-speed "fabrics" network in dual-star and full mesh topologies. A single rackmount xTCA enclosure can support Terabits/sec of total data transport across the platform. In addition to Ethernet protocols, the xTCA platform can support protocols such as Infiniband, Fibre Channel, RapidIO, PCIExpress, and Serial ATA. Finally, front-panel ports on the blades are well suited to emerging link speeds such as 40 Gbps and 100 Gbps for state-of-the-art inter-platform networking.