CQPPS: A scalable multi‐path switch fabric without back pressure

• Main Authors: Boyan Pan, Qingqing Zhou, Guo Chen
• Format: Article
• Language: English
• Published: Wiley 2021-10-01
• Series: IET Communications
• Online Access: https://doi.org/10.1049/cmu2.12236

Abstract Generally, in order to guarantee a good throughput and decrease the complexity of reassembling, the majority of current commodity routers take elaborate closed‐loop flow control schemes such as back pressure to prevent cell loss in the switch fabrics. As commodity router's port number grows larger and link rate becomes faster, the huge I/O pins and memory consumption makes these closed‐loop flow controls very difficult to implement engineeringly. This paper approaches the problem of building ultra‐large‐capacity router from a different angle. Crosspoint‐queued‐based Parallel Packet Switch (CQPPS), a highly scalable switch architecture with no need of any closed‐loop flow control schemes, is proposed. And the authors propose the Padded Frame plus Round‐Robin scheduling scheme for CQPPS architecture. By allowing potential cell loss in the switch fabrics and slightly higher light‐load delay, CQPPS achieves loss rate orders of magnitudes lower than back pressure schemes, and high‐load delay 10 times less than back pressure schemes. It also greatly reduces the complexity of engineering implementation.