A Paradigm for Processing Network Protocols in Parallel

Abstract

Network packet processing applications increasingly execute at speeds of 1-40 Gigabits per second, often running on multi-core chips that contain multithreaded network processing units (NPUs) and a general-purpose processor core. Such applications are typically programmed in a language that exposes NPU specifics needed to optimize low-level thread control and resource management. This facilitates optimization at the cost of increased software complexity and reduced portability. In contrast, our approach provides portability by combining coarse-grained, SPMD parallelism with programming in the packetC language’s high-level constructs. This paper focuses on searching packet contents for packet protocol headers. We require the host system to locate protocol headers for layers 2, 3 and 4, and to encode their offsets data in a packet information block (PIB). packetC provides descriptors, C-style structures superimposed on the packet array at runtime-calculable, user or PIB-supplied offsets. We deliver state-of-the-practice performance via an FPGA for locating layer offsets and via micro-coded interpretation that treats PIB layer offsets as a special addressing mode.