Enhanced congestion control method for servers and network lines with DPI technology

The use of Deep Packet Inspection (DPI) equipment in a network could simplify the conventional work load for system management and accelerate the control action. The authors proposed a congestion control method that uses a DPI device installed in a network to estimate overload conditions of servers or network links and, upon detecting an overload condition, resolves congestion by moving some virtual machines to other servers or rerouting some communication flows. However, since the previous paper was focused on confirming the effectiveness of using DPI technology, it assumed some restrictive conditions. This paper proposes to enhance the existing DPI-based congestion control, in order to select a solution optimal for the current conditions for cases where there are multiple candidates available for: virtual machines to be moved, physical servers to which virtual machines are to be moved, communication flows to be diverted, and routes to which communication flows are to be diverted. The paper also considers server congestion for cases where computing power congestion and bandwidth congestion occur simultaneously in a server, and link congestion for cases where the maximum allowable network delay of each communication flow is taken into consideration. Finally, the feasibility of the proposed methods is demonstrated by an evaluation system with a real DPI equipment.