Real-Time IPMI Protocol Analyzer

The Advanced Telecommunications Computing Architecture (ATCA) is a modern platform, which gains popularity, not only in telecommunication applications, but also in others fields like High Energy Physics (HEP) experiments. Computing systems based on ATCA provide high performance and efficiency and are characterized by significant reliability, availability and serviceability. ATCA offers these features because of an integrated management system realized by the Intelligent Platform Management Interface (IPMI) implemented on dedicated Intelligent Platform Management Controller (IPMC). IPMC is required on each ATCA board to fulfill the ATCA standard and is responsible for many vital procedures performed to support proper operation of ATCA system. It covers, among others, activation and deactivations of modules, monitoring of actual parameters or controlling fans. The commercially available IPMI implementations are expensive and often not suited to demands of specific ATCA applications and available hardware. Thus, many research centers and commercial companies decide to develop their own version of IPMC software. Despite precise IPMI specification of communication requests and responses, these implementations are often incompatible with each other, which leads to incorrect in-system behavior of devices equipped with IPMCs from various vendors. ATCA specifies the I²C protocol as a physical layer of IPMI. There are many devices able to monitor the I²C bus such as logic analyzers or specialized oscilloscopes. However, there is no available equipment capable of debugging IPMI as a higher level protocol. The article compares available methods of IPMI debugging and describes a custom made device prepared to monitor in realtime up to eight IPMI lines and analyze the IPMI protocol. Accessibility of this kind of equipment allows to discover errors and find the reasons of faulty behavior of the IPMC under development, greatly reduce the time to market factor and decrease costs of ATCA system development.