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A quality network infrastructure is a user demand for the increment of traffic nowadays. Due to data traffic congestion, a network's service quality cannot fulfill the user demand, especially for streaming-type traffic. For this, an appropriate queuing method can be a convenient solution for network congestion at the time of picking traffic load. In this paper, a simulation was conducted using the OPNET application to examine the feasibility of three types of queuing methods, namely first in first out (FIFO), priority queuing (PQ), and weighted fair queuing (WFQ). During the simulation, several important parameters such as delay, throughput, and response time are considered as performance metrics and compared among four types of applications as file transfer protocol (FTP), hypertext transfer protocol (HTTP), voice over internet protocol (VoIP), and video conferencing. According to the result, it is observed that WFQ provides comparatively improved results than PQ and FIFO. [ABSTRACT FROM AUTHOR]

Cloud computing is a massive amount of dynamic ad distributed resources that are delivered on request to clients over the Internet. Typical centralized cloud computing models may have difficulty dealing with challenges caused by IoT applications, such as network failure, latency, and capacity constraints. One of the introduced methods to solve these challenges is fog computing which makes the cloud closer to IoT devices. A system for dynamic congestion management brokerage is presented in this paper. With this proposed system, the IoT quality of service (QoS) requirements as defined by the service-level agreement (SLA) can be met as the massive amount of cloud requests come from the fog broker layer. In addition, a forwarding policy is introduced which helps the cloud service broker to select and forward the high-priority requests to the appropriate cloud resources from fog brokers and cloud users. This proposed idea is influenced by the weighted fair queuing (WFQ) Cisco queuing mechanism to simplify the management and control of the congestion that may possibly take place at the cloud service broker side. The system proposed in this paper is evaluated using iFogSim and CloudSim tools, and the results demonstrate that it improves IoT (QoS) compliance, while also avoiding cloud SLA violations. [ABSTRACT FROM AUTHOR]

Cloud computing is a massive amount of dynamic ad distributed resources that are delivered on request to clients over the Internet. Typical centralized cloud computing models may have difficulty dealing with challenges caused by IoT applications, such as network failure, latency, and capacity constraints. One of the introduced methods to solve these challenges is fog computing which makes the cloud closer to IoT devices. A system for dynamic congestion management brokerage is presented in this paper. With this proposed system, the IoT quality of service (QoS) requirements as defined by the service-level agreement (SLA) can be met as the massive amount of cloud requests come from the fog broker layer. In addition, a forwarding policy is introduced which helps the cloud service broker to select and forward the high-priority requests to the appropriate cloud resources from fog brokers and cloud users. This proposed idea is influenced by the weighted fair queuing (WFQ) Cisco queuing mechanism to simplify the management and control of the congestion that may possibly take place at the cloud service broker side. The system proposed in this paper is evaluated using iFogSim and CloudSim tools, and the results demonstrate that it improves IoT (QoS) compliance, while also avoiding cloud SLA violations.

This paper presents a new adaptive prioritization and fail-over mechanism for ring network adapters (RNA). Owing to the use of a shared medium in the structure of ring networks, management of network resources is very important and cannot completely be fulfilled by fixed priority strategies. An adaptive prioritization mechanism for efficient utilization of network resources is proposed in this paper. Hop-Count and the distance between source and destination are the key parameters that are included in the priority assignment procedure. Unlike the conventional ones, the arrived traffic is not put blindly into the queues thanks to the awareness of stations form status of each other. The newly introduced fail-over mechanism is based on the Power over Ethernet concept. Each station monitors the heartbeat of its neighbors and tries to keep them alive by providing their minimum required electrical power whenever a fault occurs. By doing so, not only single failure but also any successive double failure scenarios cannot disrupt data path continuity. Several simulations are carried out to assess the behavior and performance of the proposed methods in OPNET Modeler. Moreover, a high-speed USB test board is designed using Xilinx-Spartan6-lx9 FPGA to experimentally verify the performance of the proposed mechanisms.

The optimization in the configuration of network communication with time delays among field devices is a major challenging task of a networked control system (NCS). In view with the network-based model of literature, the present paper introduces the dynamic network scheduler to customize the aperiodic time delay for optimal bandwidth allocation of the network. This is achieved with the following three objectives: (a) classification of data packets among periodic and aperiodic communication using support vectors; (b) deciding the bandwidth associated with the priority weightage for aperiodic data packets; (c) simulation for fairness of NCS with dynamic network scheduler switching integrated the weighted fair queuing algorithm. The outcome of proposed dynamic network scheduler is compared with the network model of literature for reduced and bounded delays of aperiodic communication in NCS. [ABSTRACT FROM AUTHOR]

SUMMARY This paper presents RA-WF2Q+, a radio-aware version of the well-known WF2Q+ scheduler, tailored for the downlink traffic of a WiMAX system. With respect to WF2Q+, the proposed scheduler introduces the number of slots in the downlink frame as a parameter of the sharing decision process. This solution permits taking into account the information on the radio channel quality experimented by each user and, at the same time, exploiting the well-known features of WF2Q+. The simulation study comparing the performance of the proposed scheduler with those of other well-known scheduling algorithms highlights some interesting characteristics of RA-WF2Q+. In particular, it permits achieving the highest overall system throughput while guaranteeing the requested quality of service for voice applications. Only when the radio resources become scarce with respect to the total offered traffic, RA-WF2Q+ displays its opportunistic nature, favouring the users nearest to the base station. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Multiservice networks will host heterogeneous applications, requiring different qualities of service (QoS), the coexistence of which can be efficiently accounted by employing scheduling algorithms which are capable of providing different QoS simultaneously. In a previous work, we defined a reference Dual-Class (DC) paradigm, according to which rate-guaranteed flows are restrained from using more than their minimum guaranteed rate in the presence of backlogged best-effort flows and the latter share all the remaining capacity according to predetermined weights. The Timed Token Service Discipline (TTSD), which applies at the output link of a switch the same rules used to control medium access by the Timed Token Protocol, was also introduced and analyzed therein. It was proven that TTSD shares most of the capacity which is not strictly needed by the rate-guaranteed flows among the best-effort ones, thus achieving one of the goals of the DC paradigm. However, in TTSD, best-effort flows can only share the available capacity equally. In this paper, we take into account the issue of differentiating the capacity sharing among the best-effort flows: We define a Generalized TTSD (GTTSD) in which the latter actually share capacity according to predefined weights in a weighted fair queuing service discipline. Formal analysis and simulation results show that GTTSD closely approximates the DC paradigm. [ABSTRACT FROM AUTHOR]

Weighted fair queuing emerges as an elegant and effective solution to the problem of integrating real time services with strict delay constraints and high-speed data services for which significant delays cannot always be avoided. Virtual spacing is a weighted fair queuing scheduling algorithm intended to be applied in the context of the ATM based BISDN. After discussing how virtual spacing allows flexible traffic control for a variety of service types, we discuss the issue of its implementation in switching nodes. The aim of the paper is to highlight the advantages of weighted fair queuing in enabling a truly integrated services network and to propose a technologically feasible implementation. [ABSTRACT FROM AUTHOR]