Can API-RCP be TCP friendly with RED?
Yang Hong, Oliver W. W. Yang · 2008
TCP is widely implemented for congestion control in current IP networks. As the network bandwidth increases, TCP becomes oscillatory and prone to instability, regardless of the queuing scheme. As a rate-based control scheme, XCP was proposed to obtain high link utilization in high bandwidth-delay product networks, while maintaining small queue size in the routers. XCP explicit feedbacks the congestion information in the bottleneck link to the source, and brings a flurry of research interests recently. However, XCP cannot settle to zero steady-state error due to the capacity estimation error, and may lead to arbitrarily low link utilization. Using solid control theoretical analysis and design, API-RCP has solved the potential problems of XCP successfully. Furthermore, API-RCP has simpler structure for real-time implementation. Due to its satisfactory transient network performance and its stability robustness to the dramatic change of the network traffic, API-RCP is a promising algorithm for practical implementation. Why can API-RCP solve the modeling deficiency of XCP? Can API-RCP be TCP friendly with TCP/RED (the current dominant congestion control mechanism in the Internet) in the same router? To answer these two questions, we have made control theoretical comparison of API-RCP with XCP and run OPNET simulation when the APIRCP and TCP/RED co-exist in the same router.