Accessing Cloud with Disaggregated Software-Defined Router


Hua Shao, Tsinghua University; Xiaoliang Wang, Tencent and Nanjing University; Yuanwei Lu, Yanbo Yu, and Shengli Zheng, Tencent; Youjian Zhao, Tsinghua University


The last decade has witnessed a rapid growth of public clouds. More and more enterprises are deploying their applications on the cloud platform. As one of the largest public cloud providers, Tencent cloud serves tens of Tbps inbound/outbound traffic via cloud gateways for customers with diverse cloud access requirements. Traditionally, cloud gateways were built with proprietary routers. From years of experience operating cloud network, we found that commodity router based cloud gateways are hard to scale, lack of extensibility and are difficult to inter-operate with the SDN-based cloud networks. To this end, we build our own Disaggregated Software-defined Router (DSR) to serve cloud access traffic. We architecturally split cloud router functionalities into several disjoint modules: 1) an access module built out of off-the-shelf commodity switches; 2) a software-based fast and scalable forwarding module; 3) a robust and scalable routing module built with commodity servers; 4) an SDN control module for traffic management and devices configuration. All the components can be independently scaled and maintained. DSR can deliver new network features at high velocity and has sustained the rapid growth of the cloud access traffic. In this paper, we present the design, implementation and our years of operational experiences of DSR.

NSDI '21 Open Access Sponsored by NetApp

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

@inproceedings {265007,
author = {Hua Shao and Xiaoliang Wang and Yuanwei Lu and Yanbo Yu and Shengli Zheng and Youjian Zhao},
title = {Accessing Cloud with Disaggregated {Software-Defined} Router},
booktitle = {18th USENIX Symposium on Networked Systems Design and Implementation (NSDI 21)},
year = {2021},
isbn = {978-1-939133-21-2},
pages = {1--14},
url = {},
publisher = {USENIX Association},
month = apr,

Presentation Video