Self adjustable CHOKe: an active queue management algorithm for congestion control and fair bandwidth allocation

It has been reported that TCP Reno underutilizes network bandwidth, especially in High-Speed Long-Distance (HSLD) networks, while it has been widely adopted the dominant transport protocol in current Internet. Moreover, the Additive Increase Multiplicative Decrease (AIMD) congestion control algorithm of the TCP Reno has equilibrium and dynamic problems that become more and more severe as the bandwidth-delay product increases. An ideal TCP congestion control algorithm that achieves a high utilization, a small queueing delay, a stable behavior and fairness in bandwidth allocation has been major objectives of networking research in recent years. In this paper, we propose a new congestion control protocol, called TCP KWIK, a modification to the TCP Reno for HSLD networks. TCP KWIK uses delay-based feedback information to address these problems in order to stabilize a network around a fair and efficient operating point. We argue that the delay-based approach is better than the end-to-end congestion control as the networks capacity increases. Their advantage is small at low speed but decisive at high speed. The simulation results demonstrate the effectiveness of our proposed algorithm.KeywordsPacket LossCongestion ControlLoss ProbabilityRound Trip TimeCongestion WindowThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

TCP congestion control has been designed to ensure Internet stability along with fair and efficient allocation of the network bandwidth. During the last decade, many congestion control algorithms have been proposed to improve the classic Tahoe/Reno TCP Congestion control. This paper aims at evaluating and comparing three control algorithms, which are Westwood+, New Reno and Vegas TCP. Simulation scenarios are carefully designed in order to investigate goodput, fairness and friendliness provided by each of the algorithms. results show that Westwood+ TCP is friendly towards New Reno TCP and improves fairness in bandwidth allocation whereas Vegas TCP is fair but is not able to grab its bandwidth share when coexisting with Reno or in the presence of reverse traffic because of its RTT-based congestion detection mechanism. Finally results show that Westwood* remarkably improves utilization of wireless links that are affected by losses not due to congestion.

Architecture and performance of non-blocking ATM switches with shared internal queueing

The growth of real-time, streaming media application traffic in the Internet presents a number of challenges to the Internet Service Provider (ISP) because most of the real-time constraints and interactive nature of these applications render the use of unreliable User Datagram Protocol (UDP) or ineffective Transmission Control Protocol (TCP). These streaming media application flows are usually high bandwidth and long duration, which means they should utilize network congestion control to avoid congestion collapse and ensure fairness. The Internet Engineering Task Force (IETF) developed the Datagram Congestion Control Protocol (DCCP) to provide congestion control for these types of real-time applications. A major factor behind this effort was the desire to eliminate the duplication of effort and potential for error resulting from each application implementing its own congestion control. The emergence of new concept of centrally controlled Software-Defined Networks (SDN), really take advantage of the information available at the central controller to improve network performance. In this paper, the performance of video streaming was examine, and it is shown that DCCP capable of having a fairly bandwidth tolerance to other network traffic than typical real-time, streaming media congestion control methods. Given fair bandwidth allocation using OpenFlow protocol, DCCP provides equivalent or better video quality.

Internet of Things (IoT) has played a tremendous change in the Information Technology (IT) environments, and thus its importance has also been realized within Intelligent Home Networks (IHNs). IHNs ensure comfort, safety, healthcare, automation, energy conservation, and remote management to devices and users. However, we have realized that more advanced devices and services continue to be introduced and used in IHNs. This has led to competitions of the limited available network resources, services, and bandwidth. In this paper, we propose a Novel Dynamic Bandwidth Allocation (NoDBA) algorithm to deal with bandwidth management and allocation. The algorithm integrates two algorithms, namely; Offline Cooperative Algorithm (OCA) and Particle Swarm Optimization (PSO). PSO defines the priority limits for subnets and nodes in the network. Meanwhile, OCA facilitates dynamic bandwidth allocation in the network. Network Simulator-2 (NS-2) was used to simulate and evaluate NoDBA and showed improved results compared to the traditional bandwidth allocation algorithm.

CSFQ is designed as an open loop controller to provide fair best effort service, which supervises the bandwidth consumption of pre-flow and has become helpless after P2P flows dominate the traffic of the Internet. Token- Based Congestion Control (TBCC) is based on a closed loop congestion control principle, which restricts the token resource consumed by an end-user and provides fair services with O(1) complexity. As Self-Verifying CSFQ, it is heavy load to police inter-domain traffic for lack of trust. In this paper, Token- Limited Congestion Control (TLCC) is presented, which appends inter-domain congestion control to TBCC. TLCC provides the fixed cost to the inter-domain congestion charging with O(1) complexity. By simulations, it is demonstrated that TLCC can provide stable and fair bandwidth allocation across the domain border.

In this research, we focused on fair bandwidth allocation on the Internet. The Internet provides communication services based on exchanged packets. The bandwidth available for each customer is often fluctuated. Fair bandwidth allocation is an important issue for ISPs to gain customer satisfaction. Static bandwidth allocation allows an exclusive bandwidth for specific traffic. Although it gives communications a QoS guarantee, it requires muany bandwidth resources as known as over-provisioning. In contrast with static dynamic control allocates bandwidth resources dynamically. It therefore utilizes bandwidth use more effectively. However, it needs control overhead in monitoring traffic and estimating the optimum allocation. The Transmission Control Protocol, or TCP is the dominant protocol on the Internet. It is also equipped with a traffic-rate-control mechanism. An adaptive bandwidth-allocation mechanism must control traffic that is under TCP Rapid feedback makes it possible to gain an advantage over TCP In this paper, we propose an Adaptive Bandwidth Allocation (ABA) mechanism as a feedback system for MPLS. Our proposal allows traffic to be regulated adaptively as its own weight value which can be assigned by administrators. The feedback bandwidth allocation in the previous work needs control delay in collecting network status along the communication path. We call this round-trip feedback control. Our proposal, called feedback control, collects network status in half the time of roundtrip delay. We compare the performance of our one-way feedback-based mechanism and traditional feedback control under a simulation environment. We demonstrate the advantages of our rapid feedback control has using experimental results.

The network resource allocation in SDN for control applications is becoming a key problem in the near future because of the conflict between the need of the flow-level flexibility control and the limited capacity of flow table. Based on the analysis of the difference of the definition of network resource between SDN and traditional IP network, the idea of the integrated allocation of link bandwidth and flow table for multiple control applications in SDN is proposed in this paper. Furthermore, a price-based joint allocation model of network resource in SDN is built by introducing the price for each of the resources, which can get the proportional fair allocation of link bandwidth and the minimum global delay at the same time. We have also designed a popular flow scheduling policy based on the proportional fair allocation of link bandwidth in order to achieve the minimum global delay. A flow scheduling module has been implemented and evaluated in Floodlight, named virtual forwarding space (VFS). VFS can not only implement the fair allocation of link bandwidth and minimum delay flow scheduling in data plane but also accelerate packet forwarding by looking up flow cache in control plane.

The explosive increase in the volume and variety of Internet traffic has placed a growing emphasis on congestion control and fairness in Internet routers. Approaches to the problem of congestion, such as active queue management schemes like Random Early Detection (RED) use congestion avoidance techniques and are successful with TCP flows. Approaches to the problem of fairness, such as Fair Random Early Drop (FRED), keep per-flow state and punish misbehaved, non-TCP flows. Unfortunately, these punishment mechanisms also result in a significant performance drop for multimedia flows that use flow control. We extend Class-Based Threshold (CRT) [12], and propose a new active queue management mechanism as an extension to RED called Dynamic Class-Based Threshold (D- CBT) to improve multimedia performance on the Internet. Also, as an effort to reduce multimedia jitter, we propose a lightweight packet scheduling called Cut-In Packet Scheduling (ChIPS) as an alternative to FIFO packet scheduling. The performance of our proposed mechanisms is measured, analyzed and compared with other mechanisms (RED and CBT) in terms of throughput, fairness and multimedia jitter through simulation using NS. The study shows that D-CBT improves fairness among different classes of flows and ChIPS improves multimedia jitter without degrading fairness.

In this paper, we present a theoretical framework and a distributed mechanism for fair bandwidth allocation on a network with various bottleneck links. In our model, a user is guaranteed a minimum bandwidth and charged a price for a bandwidth capacity request. We defined a utility function that reflects user's bandwidth demand when the user requests the bandwidth capacity. We then present a non-cooperative game with social welfare function to resolve users' conflicting bandwidth capacity requests at bottleneck links. We also show that our proposed game-theoretic solution guarantees fair bandwidth allocation as defined in our residual capacity fairness. In order to guarantee the minimum bandwidth requirement, we integrate an admission control in our solution. However, global optimal admission conditions are not easy to implement for large networks. We therefore propose a distributed admission scheme. As a result, the paper presents fair and practical distributed algorithms for bandwidth allocation and admission control in enterprise networks. Our simulation and evaluation study show that the distributed approach is sufficiently close to the global optimal solution.

In this era of optical communication, the passive optical network (PON) having multiple optical line terminals (multi-OLT) will play a vital role for both the data and voice communications of multiple service providers. For downstream data transmission of multi-OLT PON, the existing algorithms are not effective to allocate bandwidth among different service providers. Because, the existing scheme does not provide fairness in sharing of downstream bandwidth. This paper proposes a new downstream bandwidth allocation scheme for multi-OLT PON system called fair and weight-based bandwidth allocation (FWBA) algorithm. In the proposed scheme, we have considered a multi-OLT PON system for convergence of cable television, fiber-to-the-home, wireless sensor, and femto networks. The performances of the FWBA scheme have been analyzed on the basis of transmission delay, idle-time as well as traffic handling capacity. The comparative analysis of simulation results show that the FWBA scheme performs better than non-weight-based DBA (NWBA) scheme.

Heterogeneous networks (HetNets) composed of macrocells and small cells are expected to improve the transmission performance of users significantly. Designing efficient resource allocation schemes, specifically, bandwidth allocation and power allocation schemes for HetNets is of particular importance for it may affect user quality of service (QoS) and network performance severely. In this paper, we consider the resource allocation problem of a HetNet composed of a macrocell and a number of femtocells and propose a resource characteristic and user QoS oriented bandwidth and power allocation algorithm for the femto base stations (FBSs) which share spectrum with the macro base station. By taking into account the service requirements of the femto user equipments (FUEs) and the bandwidth resource characteristics of the network, various bandwidth resource allocation schemes are proposed. Particularly, in the case of slightly insufficient bandwidth resource, we propose a bankruptcy game based bandwidth resource allocation algorithm for the FBSs, and solve the bandwidth allocation problem by means of Shapley value method. To stress the tradeoff between data rate and power consumption, we examine the energy efficiency of the FBSs and formulate the power allocation problem as a multi-objective optimization problem with the objectives of maximizing the energy efficiency of all the FBSs. The optimal power allocation strategy can be obtained by solving the optimization problem via ideal point method and generic algorithm. Simulation results demonstrate the efficiency of the proposed algorithm.

Congestion in Wireless Multimedia Sensor Networks (WMSN) may cause packet loss, buffer overflow and increases queueing delay, which has a significant negative impact on the network performance and reliability. This problem imposes more resource constraints that involve energy consumption and buffer size to meet additional requirements such as desired buffer size and limited amount of packet loss. One of the fundamental issues of congestion problem in such networks is the queue management. In fact, handling congestion without considering flexible buffer management and queueing methods, stay insignificant against dropping rate and packet loss. Consequently, a novel congestion control approach is needed to overcome these problems. In this paper, a new queue management mechanism called: Priority Queue Management based Explicit Congestion Control (PQMECC) is proposed and modeled using Stochastic Automata Networks, which are appropriate for modeling and analyzing complex systems with interacting components and complex synchronization. The congestion control technique used in PQMECC is based on priority, load repartition mechanism and explicit congestion notification which is generated only if the congestion reaches the threshold value.

In this article, which has an important role in the regulation of the flow of traffic in computer networks is discussed queue management. Queue management algorithms are widely used today introduced the working principles are described briefly. NS-3 network simulator program was used for queue management algorithms comparison of performance. On NS-3 network simulator, DROP TAIL and RED queue management algorithms have been tested on various topologies and performance evaluations were made. Furthermore, the studies are compared with results obtained previously. The data obtained from these tests and studies those evaluated, RED algorithms that use probabilistic methods and threshold values have been found to be more successful.

Achieving efficient and fair bandwidth allocation while minimizing packet loss and bottleneck queue in high bandwidth-delay product networks has long been a daunting challenge. Existing end-to-end congestion control (e.g., TCP) and traditional congestion notification schemes (e.g., TCP+AQM/ECN) have significant limitations in achieving this goal. While the XCP protocol addresses this challenge, it requires multiple bits to encode the congestion-related information exchanged between routers and end-hosts. Unfortunately, there is no space in the IP header for these bits, and solving this problem involves a non-trivial and time-consuming standardization process. In this paper, we design and implement a simple, low-complexity protocol, called variable-structure congestion control protocol (VCP), that leverages only the existing two ECN bits for network congestion feedback, and yet achieves comparable performance to XCP, i.e., high utilization, negligible packet loss rate, low persistent queue length, and reasonable fairness. On the downside, VCP converges significantly slower to a fair allocation than XCP. We evaluate the performance of VCP using extensive ns2 simulations over a wide range of network scenarios and find that it significantly outperforms many recently-proposed TCP variants, such as HSTCP, FAST, CUBIC, etc. To gain insight into the behavior of VCP, we analyze a simplified fluid model and prove its global stability for the case of a single bottleneck shared by synchronous flows with identical round-trip times.