Data Center TCP in ns-3: Implementation, Validation and Evaluation

Abstract

Data Center TCP (DCTCP) is a standard congestion control scheme used to provide high burst tolerance, low latency and high throughput in Data Center Networks (DCNs). It uses in-network feedback obtained through Explicit Congestion Notification (ECN) to scale the congestion window (cwnd). Recently, there have been significant efforts to extend DCTCP to provide low latency transport (e.g., TCP Prague) in a Wide Area Network, but with congestion control and in-network queuing mechanisms that are backward compatible with legacy implementations. This paper presents the implementation and validation of a new ns-3 model for DCTCP which can be used to implement its extensions, such as TCP Prague. The proposed model is verified and validated by comparing it to the Linux model of DCTCP by using ns-3 Direct Code Execution (DCE), a framework to run ns-3 simulations using Linux network stack. The results obtained from this comparison show that the ns-3 model and Linux model of DCTCP exhibit similar characteristics.