IP Address Lookup by Using GPU

We present a novel parallel IP address lookup architecture based on graphics processing unit (GPU) via compute unified device architecture (CUDA). Our architecture consists of two functions: (1) host function and (2) device function. The host function is executed by a CPU to construct and update the data structure of IP address lookup executed by the device function in a GPU. Both host and device functions are executed simultaneously to fully utilize computational resources. To shorten the lookup time, a trie-based data structure optimized for CUDA is developed. The trie-based data structure uses multi-bit stride to shorten the trie depth and also improves the efficiency of texture cache in GPUs. The experimental results show that a low-end G92 GPU can achieve a throughput of more than 1.3 billion packets per second for IPv4 routing tables with more than 350K prefixes while a high-end GT200 GPU can further double the performance. By employing dual data structures, the implementation can support several hundred thousand updates per second.