Better by a HAIR: Hardware-Amenable Internet Routing

Routing protocols are implemented in the form of software running on a general-purpose microprocessor. However, conventional software-based router architectures face significant scaling challenges in the presence of ever-increasing routing table growth and churn. Recent advances in programmable hardware and high-level hardware description languages provide the opportunity to implement BGP directly at the hardware layer. Hardware-based implementation allows designs to take advantage of the parallelization and customizability of the underlying hardware to improve performance. As a first step in this direction, we design and implement a hardware-based BGP architecture. To understand the challenges in doing this, we propose an architecture and logical design for the core components of BGP running as a logical circuit in an FPGA. We then enumerate sources of complexity and performance bottlenecks, and derive modifications to BGP that reduce complexity of hardware offloading. Our results based on update traces from core Internet routers indicate an order of magnitude improvement in processing time and throughput.