grout stands for Graph Router. It is a DPDK based network processing application. It uses the rte_graph library for data path processing. It was recently accepted as a hosted project on dpdk.org. Its main purpose is to simulate a network function or a physical router for testing/replicating real (usually closed source) VNF/CNF behavior with an opensource tool. It comes with a client API to configure it over a standard UNIX socket and a CLI that uses that API. The CLI can be used as an interactive shell, but also in scripts one command at a time, or by batches. This talk will present the project and my journey with writing a DPDK application from scratch using rte_graph. I will also make some demonstrations of its capabilities and performance.