Biblio

Many applications are bandwidth consuming but may tolerate longer flow completion times. Multipath protocols, such as multipath TCP (MPTCP), can offer bandwidth aggregation and resilience to link failures for such applications, and low priority congestion control (LPCC) mechanisms can make these applications yield to other time-sensitive ones. Properly combining the above two can improve the overall user experience. However, the existing LPCC mechanisms are not adequate for MPTCP. They do not take into account the characteristics of multiple network paths, and cannot ensure fairness among the same priority flows. Therefore, we propose a multipath LPCC mechanism, i.e., Dynamic Coupled Low Extra Delay Background Transport, named DC-LEDBAT. Our scheme is designed based on a standardized LPCC mechanism LEDBAT. To avoid unfairness among the same priority flows, DC-LEDBAT trades little throughput for precisely measuring the minimum delay. Moreover, to be friendly to single-path LEDBAT, our scheme leverages the correlation of the queuing delay to detect whether multiple paths go through a shared bottleneck. Then, DC-LEDBAT couples the congestion window at shared bottlenecks to control the sending rate. We implement DC-LEDBAT in a Linux kernel and experimental results show that DC-LEDBAT can not only utilize the excess bandwidth of MPTCP but also ensure fairness among the same priority flows.

Satellite networks are booming to provide high-speed and low latency Internet access, but the transport layer becomes one of the main obstacles. Legacy end-to-end TCP is designed for terrestrial networks, not suitable for error-prone, propagation delay varying, and intermittent satellite links. It is necessary to make a clean-slate design for the satellite transport layer. This paper introduces a novel Information-centric Hop-by-Hop transport layer design, INTCP. It carries out hop-by-hop packets retransmission and hop-by-hop congestion control with the help of cache and request-response model. Hop-by-hop retransmission recovers lost packets on hop, reduces retransmission delay. INTCP controls traffic and congestion also by hop. Each hop tries its best to maximize its bandwidth utilization and improves end-to-end throughput. The capability of caching enables asynchronous multicast in transport layer. This would save precious spectrum resources in the satellite network. The performance of INTCP is evaluated with the simulated Starlink constellation. Long-distance communication with more than 1000km is carried out. The results demonstrate that, for the unicast scenario INTCP could reduce 42% one-way delay, 53% delay jitters, and improve 60% throughput compared with the legacy TCP. In multicast scenario, INTCP could achieve more than 6X throughput.

Congestion control is one of the essential keys to enhance network efficiency so that the network can perform well even in the case of packet drop. This problem is even more challenging in Information-Centric Networking (ICN), a typical Future Internet design, which employs the packet flooding policy for forwarding the information. To diminish the high traffic load due to the huge number of packets in the era of the Internet of Things (IoT), this paper proposes an effective caching and forwarding algorithm to diminish the congestion rate of the IoT wireless sensor in ICN. The proposed network system utilizes accumulative popularity-based delay transmission time for forwarding strategy and includes the consecutive chunks-based segment caching scheme. The evaluation results using ndnSIM, a widely-used ns-3 based ICN simulator, demonstrated that the proposed system can achieve less interest packet drop rate, more cache hit rate, and higher network throughput, compared to the relevant ICN-based benchmarks. These results prove that the proposed ICN design can achieve higher network efficiency with a lower congestion rate than that of the other related ICN systems using IoT sensors.

The router's buffer size imposes significant impli-cations on the performance of the network. Network operators nowadays configure the router's buffer size manually and stati-cally. They typically configure large buffers that fill up and never go empty, increasing the Round-trip Time (RTT) of packets significantly and decreasing the application performance. Few works in the literature dynamically adjust the buffer size, but are implemented only in simulators, and therefore cannot be tested and deployed in production networks with real traffic. Previous work suggested setting the buffer size to the Bandwidth-delay Product (BDP) divided by the square root of the number of long flows. Such formula is adequate when the RTT and the number of long flows are known in advance. This paper proposes a system that leverages programmable switches as passive instruments to measure the RTT and count the number of flows traversing a legacy router. Based on the measurements, the programmable switch dynamically adjusts the buffer size of the legacy router in order to mitigate the unnecessary large queuing delays. Results show that when the buffer is adjusted dynamically, the RTT, the loss rate, and the fairness among long flows are enhanced. Additionally, the Flow Completion Time (FCT) of short flows sharing the queue is greatly improved. The system can be adopted in campus, enterprise, and service provider networks, without the need to replace legacy routers.

Recently, methods are studied to overcome various problems for Named Data Networking(NDN). Among them, a new method which can overcome content storm problem is required to reduce network congestion and deliver content packet to consumer reliably. According to the various studies, the content storm problems could be overcame by scoped interest flooding. However, because these methods do not considers not only network congestion ratio but also the number another different paths, the correspond content packets could be transmitted unnecessary and network congestion could be worse. Therefore, in this paper, we propose a new content forwarding method for NDN to overcome the content storm problem. In the proposed method, if the network is locally congested and another paths are generated, an intermediate node could postpone or withdraw the content packet transmission to reduce congestion.

In this paper, we propose a robust Nash strategy for a class of uncertain Markov jump delay stochastic systems (UMJDSSs) via static output feedback (SOF). After establishing the extended bounded real lemma for UMJDSS, the conditions for the existence of a robust Nash strategy set are determined by means of cross coupled stochastic matrix inequalities (CCSMIs). In order to solve the SOF problem, an heuristic algorithm is developed based on the algebraic equations and the linear matrix inequalities (LMIs). In particular, it is shown that robust convergence is guaranteed under a new convergence condition. Finally, a practical numerical example based on the congestion control for active queue management is provided to demonstrate the reliability and usefulness of the proposed design scheme.

Selecting the best path in multi-path heterogeneous networks is challenging. Multi-path TCP uses by default a scheduler that selects the path with the minimum round trip time (minRTT). A well-known problem is head-of-line blocking at the receiver when packets arrive out of order on different paths. We shed light on another issue that occurs if scheduling have to deal with deep queues in the network. First, we highlight the relevance by a real-world experiment in cellular networks that often deploy deep queues. Second, we elaborate on the issues with minRTT scheduling and deep queues in a simplified network to illustrate the root causes; namely the interaction of the minRTT scheduler and loss-based congestion control that causes extensive bufferbloat at network elements and distorts RTT measurement. This results in extraordinary large buffer sizes for full utilization. Finally, we discuss mitigation techniques and show how alternative congestion control algorithms mitigate the effect.

In wireless sensor networks (WSNs), congestion control is a very essential region of concern. When the packets that are coming get increased than the actual capacity of network or nodes results into congestion in the network. Congestion in network can cause reduction in throughput, increase in network delay, and increase in packet loss and sensor energy waste. For that reason, new complex methods are mandatory to tackle with congestion. So it is necessary to become aware of congestion and manage the congested resources in wireless sensor networks for enhancing the network performance. Diverse methodologies for congestion recognition and prevention have been presented in the previous couple of years. To handle some of the problems, this paper exhibits a new technique for controlling the congestion. An efficient and reliable routing protocol (ERRP) based on bio inspired algorithms is introduced in this paper for solving congestion problem. In the proposed work, a way is calculated to send the packets on the new pathway. The proposed work has used three approaches for finding the path which results into a congestion free path. Our analysis and simulation results shows that our approach provides better performance as compared to previous approaches in terms of throughput, packet loss, delay etc.

Mitigating the effect of Distributed Denial of Service (DDoS) attacks in wired/wireless networks is a problem of extreme importance. The present paper investigates this problem and proposes a secure AQM to encounter the effects of DDoS attacks on queue's router. The employed method relies on modelling the TCP/AQM system subjected to different DoS attack rate where the resulting closed-loop system is expressed as new Markovian Jump Linear System (MJLS). Sufficient delay-dependent conditions which guarantee the syntheses of a stabilizing control for the closed-loop system with a guaranteed cost J* are derived. Finally, a numerical example is displayed.

Vehicular Ad-Hoc Network, or VANETs, is a form of MANET, through which cars will exchange messages to detect dangerous situations and announce them to drivers. In VANETs, vehicles (nodes) are characterized by a high dynamics and high mobility, in addition to the high rate of topology change and density variability. Quality of service in VANETs represents a major challenge, not yet solved, due to the characteristics and strict constraints of VANETs. In order to improve the performance and reliability of message dissemination on VANETs, congestion control must be taken into account. Many studies asserted that proper congestion control algorithms are essential to ensure an efficient network operation. However, most of the existing congestion control solutions have limitations. In this paper, we propose congestion control algorithm as solution to avoid congestion in VANETs environment. The proposed solution is based on a combination of two approaches: the event-oriented and the measurement-based, with message scheduling. The proposed solution is to reduce congestion and increase reliability to VANETs by assigning higher priority to critical security message.

Congestion Control (CC) algorithms are essential to quickly restore the network performance back to stable whenever congestion occurs. A majority of the existing CC algorithms are implemented at the transport layer, mostly coupled with TCP. Over the past three decades, CC algorithms have incrementally evolved, resulting in many extensions of TCP. A thorough evaluation of a new TCP extension is a huge task. Hence, the Internet Congestion Control Research Group (ICCRG) has proposed a common TCP evaluation suite that helps researchers to gain an initial insight into the working of their proposed TCP extension. This paper presents an implementation of the TCP evaluation suite in ns-3, that automates the simulation setup, topology creation, traffic generation, execution, and results collection. We also describe the internals of our implementation and demonstrate its usage for evaluating the performance of five TCP extensions available in ns-3, by automatically setting up the following simulation scenarios: (i) single and multiple bottleneck topologies, (ii) varying bottleneck bandwidth, (iii) varying bottleneck RTT and (iv) varying the number of long flows.