# New RED-Type TCP-AQM Algorithms Based on Beta Distribution Drop Functions
## 1 Introduction  
Over the last few decades, the Internet has become increasingly faster by many orders of magnitude, but at the same time the number of users has increased, along with a huge deployment of Internet-based applications, and with a multitude of bandwidth and latency requirements. This growth in data flow has resulted in increased network traffic congestion, which, if not properly managed, could lead to a considerable decrease in performance, a critical factor for any Internet service. The TCP transport protocol has become the standard for data communications, being the most common type of data flow on the Internet. The most popular network applications (FTP, TELNET, Web Access, etc.) use TCP protocol in their communications. This, together with the massive use of Voice over Internet Protocol (VoIP) applications, online games, financial exchanges, etc., has caused buffers to fill up, resulting in the phenomenon known as bufferbloat [1], characterized by high latency and massive discarding of packets over long periods of time, leading to poor quality of service for the end user. Congestion control is a critical part of the Transmission Control Protocol (TCP), which directly influences transport performance. TCP is the dominant transport layer protocol on the Internet. In general, there are two congestion control mechanisms: (1) end-to-end congestion controls, which are are approaches adopted by TCP and are achieved mainly at the transport layer; and (2) network-assisted congestion controls, which are controls adopted by routers. This mechanism uses router queue size and/or delay to monitor thecongestion state of the network. To meet the demands of Internet users and applications, research both in academic and industrial environments has focused on improving these two control mechanisms to achieve high performance and avoid data traffic collapse. This paper is concerned with the second approach, and aims to design a new congestion control mechanism to be implemented at the router. For those readers interested in the first approach, the surveys [2; 3] collect the main transport protocols that have been proposed in recent years. The main objective of congestion control mechanisms is to keep the network operating fairly close to its nominal capacity, even when faced with extreme overload. This objective is achieved by acting according to two fundamental premises. The first is to prevent network congestion before it occurs and to dissolve congestion if it cannot be avoided. The second is to provide a fairness service to different connections, along with support for various Internet application domains with varying quality of service (QoS) requirements. Designing good congestion control mechanisms is extremely difficult; the specific characteristics of the connection and each individual link can significantly affect performance, often in unpredictable ways. Active Queue Management (AQM) algorithms are algorithms implemented in routers that act on the buffer queue to control its length so that efficient congestion control of the system is achieved. Such management also allows TCP to do its job of sharing links properly, without which it cannot function as intended. The primary goal of an AQM is to prevent congestion before it occurs and, if it has already occurred, to try to control it. AQM mechanisms act on the length of queues in buffers to achieve lower delay, and try to absorb short-term variations (e.g., bursts), thus playing a crucial role in congestion control on the Internet. Numerous AQM schemes have been proposed in recent years to properly manage queues to avoid undesirable effects such as bufferbloat, link underutilization, large variations in queuing delays, etc. The truth is that there is no one algorithm that has dominated over the others, since network environments are very varied, and network traffic very changeable, so each algorithm has advantages and disadvantages according to those environments.