Improving Mission Assurance using Bit-True Hitless Data Path Selection at 10 Gbps #220

The packetization presents several problems in terms of protocol adaptation and data continuity as switching occurs. This paper addresses such issues and illustrates methods to overcome such adversity as well as alternatives for reuse across multiple domains. The DoD, Intelligence Community and NASA can benefit from higher mission assurance as the network-centric operation transformation continues. The data streams exhibit significant delay between them as well as varying error rates. These data flows require careful alignment and as the data rate increases to 10 Gbps or greater, particular attention must be paid in obtaining the desired bit-true alignment. The equipment contains the necessary switching information but only maintains this control knowledge embedded within the equipment. As such, an external user of this equipment does not have visibility or control of these embedded switching paths. Forward error correction (FEC) also plays a major role in establishing the highest quality information flow. One method that overcomes this limitation delves down to the bit level, aligning each redundant source on the bit boundary. This paper describes such a method of switching on a bit-by-bit, or bit-true basis. This includes adjusting for delays between each source, buffering to account for advancement or retardation of the sources, sorting based on internal or external control parameters, and selecting the optimum source for output. Results presented by the paper include technology realizations such as field-programmable gate array (FPGA) implementations, general parameter measurement and protocol adaptations necessary to provide such robust switching. Methods to handle the embedded FEC are discussed with associated ramifications. Overall, the paper presents a general method of maintaining high-reliability in redundant sourced systems with specific analysis applied to high-speed (10 Gbps) information transfer and network implementation