S S symmetry Article Weight Queue Dynamic Active Queue Management Algorithm Mahmoud Baklizi Department of Computer Networks Systems, The World Islamic Science & Education University W.I.S.E, Amman 00962, Jordan; [email protected] Received: 16 November 2020; Accepted: 11 December 2020; Published: 14 December 2020 Abstract: The current problem of packets generation and transformation around the world is router congestion, which then leads to a decline in the network performance in term of queuing delay (D) and packet loss (PL). The existing active queue management (AQM) algorithms do not optimize the network performance because these algorithms use static techniques for detecting and reacting to congestion at the router buffer. In this paper, a weight queue active queue management (WQDAQM) based on dynamic monitoring and reacting is proposed. Queue weight and the thresholds are dynamically adjusted based on the traffic load. WQDAQM controls the queue within the router buffer by stabilizing the queue weight between two thresholds dynamically. The WQDAQM algorithm is simulated and compared with the existing active queue management algorithms. The results reveal that the proposed method demonstrates better performance in terms mean queue length, D, PL, and dropping probability, compared to gentle random early detection (GRED), dynamic GRED, and stabilized dynamic GRED in both heavy or no-congestion cases. In detail, in a heavy congestion status, the proposed algorithm overperformed dynamic GRED (DGRED) by 13.3%, GRED by 19.2%, stabilized dynamic GRED (SDGRED) by 6.7% in term of mean queue length (mql). In terms of D in a heavy congestion status, the proposed algorithm overperformed DGRED by 13.3%, GRED by 19.3%, SDGRED by 6.3%. As for PL, the proposed algorithm overperformed DGRED by 15.5%, SDGRED by 19.8%, GRED by 86.3% in term of PL. Keywords: congestion algorithms; GRED; SDGRED; implementation; queue weight 1. Introduction Computer network devices are utilized in smart homes, smart buildings, organizations, universities, companies, and countries. The wide distribution of computer networks is a consequence of many factors, and among these is the emerging of the Internet-of-Things (IoT). The ever-increasing use of computer networks has resulted in increasing computer crimes and cyber-attacks. Moreover, the connected terminals throughout these networks add a heavy load on the network resources and devices [1]. As a result, the amount of data transferred across the network devices, such as computers and routers, greatly increases. To share the network resources [2–6], the transferred data are divided into packets. Every device that generates packets must be temporarily stored at the router buffer before forwarding to the next router or its destination. When the router buffer becomes full, congestion occurs, and it will lead to the case of packet loss (Figure1)[7–10]. Symmetry 2020, 12, 2077; doi:10.3390/sym12122077 www.mdpi.com/journal/symmetry Symmetry 2020, 12, 2077 2 of 16 Symmetry 2020, 12, x FOR PEER REVIEW 2 of 15 FigureFigure 1. 1. CongestedCongested router. router. TCPTCP protocol hashas its its congestion congestion control, control, however, however, congestion congestion control control at the at router the router buffer buffer that results that resultsin using in TCP using over TCP the underlyingover the underlying networks isnetworks not considered is not [ 4considered,11]. 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Section 6 provides the conclusion. 2. Related Works Several algorithms were created to manage the queue and control congestion at the router buffer [3,8,11,23]. The default algorithm for congestion control is the drop tail (DT) algorithm [24]. This algorithm uses the first-in first-out (FIFO) principle, in which the arriving packets are dropped once the router buffer overflows, as illustrated in Figure 2 [11]. The DT does not have thresholds, and when the maximum capacity of the router buffer is reached, the new arriving packets are dropped directly. Symmetry 2020, 12, 2077 3 of 16 2. Related Works Several algorithms were created to manage the queue and control congestion at the router buffer [3,8,11,23]. The default algorithm for congestion control is the drop tail (DT) algorithm [24]. This algorithm uses the first-in first-out (FIFO) principle, in which the arriving packets are dropped once the