Streaming architecture for packet parsing

Abstract

Apparatus and associated methods relate to packet header field extraction as defined by a high level language and implemented in a minimum number of hardware streaming parsing stages to speculatively extract header fields from among multiple possible header sequences. In an illustrative example, the number of stages may be determined from the longest possible header sequence in any received packet. For each possible header sequence, one or more headers may be assigned to each stage, for example, based on a parse graph. Each pipelined stage may resolve a correct header sequence, for example, by sequentially extracting length and transition information from an adjacent prior stage to determine offset of the next header. By speculatively extracting selected fields from every possible position in each pipeline stage, a correct value may be selected using sequential hardware streaming pipelines to substantially reduce parsing latency.