Quality of Service (QoS) generally refers to measurable like latency and throughput, things that directly affect the user experience. Queuing (the most popular QoS tool) involves choosing the packets to be sent based ...Quality of Service (QoS) generally refers to measurable like latency and throughput, things that directly affect the user experience. Queuing (the most popular QoS tool) involves choosing the packets to be sent based on something other than arrival time. The Active queue management is important subject to manage this queue to increase the effectiveness of Transmission Control Protocol networks. Active queue management (AQM) is an effective means to enhance congestion control, and to achieve trade-off between link utilization and delay. The de facto standard, Random Early Detection (RED), and many of its variants employ queue length as a congestion indicator to trigger packet dropping. One of these enhancements of RED is FRED or Fair Random Early Detection attempts to deal with a fundamental aspect of RED in that it imposes the same loss rate on all flows, regardless of their bandwidths. FRED also uses per-flow active accounting, and tracks the state of active flows. FRED protects fragile flows by deterministically accepting flows from low bandwidth connections and fixes several shortcomings of RED by computing queue length during both arrival and departure of the packet. Unlike FRED, we propose a new scheme that used hazard rate estimated packet dropping function in FRED. We call this new scheme Enhancement Fair Random Early Detection. The key idea is that, with EFRED Scheme change packet dropping function, to get packet dropping less than RED and other AQM algorithms like ARED, REM, RED, etc. Simulations demonstrate that EFRED achieves a more stable throughput and performs better than current active queue management algorithms due to decrease the packets loss percentage and lowest in queuing delay, end to end delay and delay variation (JITTER).展开更多
This paper proposed an Integrated Random Early Detection(IRED)method that aims to resolve the problems of the queue-based AQM and loadbased AQM and gain the benefits of both using indicators from both types.The arriva...This paper proposed an Integrated Random Early Detection(IRED)method that aims to resolve the problems of the queue-based AQM and loadbased AQM and gain the benefits of both using indicators from both types.The arrival factor(e.g.,arrival rate,queue and capacity)and the departure factors are used to estimate the congestion through two integrated indicators.The utilized indicators are mathematically calculated and integrated to gain unified and coherent congestion indicators.Besides,IRED is built based on a new dropping calculation approach that fits the utilized congestion indicators while maintaining the intended buffer management criteria,avoiding global synchronization and enhancing the performance.The results showed that IRED,compared to RED,BLUE,ERED,FLRED,EnRED and DcRED,decreased packet delay and loss under various network status.Specifically,the results showed that in heavy and moderate traffic,the proposed IRED method outperformed the state-of-the-art methods in loss and delay by 18% and 10.6%,respectively.展开更多
为了提高响应流和非响应流之间的公平性,提出了一种基于速率公平的RED改进算法——RF-RED(ratefairness random early detection).该算法在路由器端计算UDP流的平均速率并与TCP友好流速率进行比较,根据比较结果动态调整UDP流和TCP流的...为了提高响应流和非响应流之间的公平性,提出了一种基于速率公平的RED改进算法——RF-RED(ratefairness random early detection).该算法在路由器端计算UDP流的平均速率并与TCP友好流速率进行比较,根据比较结果动态调整UDP流和TCP流的最大丢包率,最后使用RED算法分别更新UDP流和TCP流的实际丢包率.通过使用RF-RED算法,UDP流在瓶颈链路上成为TCP友好流,同时瓶颈带宽得到了公平利用.仿真结果验证了该算法的有效性.展开更多
针对随机早期检测(random early detection,RED)算法在慢速拒绝服务攻击(low-rate deny of serv-ice,LDoS)面前的脆弱性问题,本文通过对比路由器分别在RED和尾丢弃Drop-Tail算法管理下遭受LDoS攻击时的队列平均占用率及吞吐量,指出虽然...针对随机早期检测(random early detection,RED)算法在慢速拒绝服务攻击(low-rate deny of serv-ice,LDoS)面前的脆弱性问题,本文通过对比路由器分别在RED和尾丢弃Drop-Tail算法管理下遭受LDoS攻击时的队列平均占用率及吞吐量,指出虽然路由器在RED算法下具有较大的空闲缓冲区,却不能对网络流量攻击起到缓冲作用.仿真对比实验表明,LDoS攻击使得路由器在RED下比Drop-Tail具有更大的链路损失带宽.指出现有LDoS的防范和检测方法的不足,构造了一种分布式LDoS攻击模型并给出一组模型实例,该模型说明现有突发流量检测方法不足以弥补RED脆弱性,也说明网络流量行为的关联复杂性.展开更多
拥塞控制(congestion control)机制是确保InternetQoS的关键因素,随机早期检测(Random Early D etection,RED)算法是提高网络服务质量、解决网络阻塞的重要算法。针对网关的到达队列来说,丢包率的算法采用RED基本思想中与平均队列长度...拥塞控制(congestion control)机制是确保InternetQoS的关键因素,随机早期检测(Random Early D etection,RED)算法是提高网络服务质量、解决网络阻塞的重要算法。针对网关的到达队列来说,丢包率的算法采用RED基本思想中与平均队列长度呈线性的关系并不合适,提出了立方RED算法。算法对RED算法进行了改进,使流丢包率与平均队列长度呈立方函数关系,通过NS-2仿真软件研究表明,算法可以有效的增加了网关的吞吐量、减少丢包率。展开更多
文摘Quality of Service (QoS) generally refers to measurable like latency and throughput, things that directly affect the user experience. Queuing (the most popular QoS tool) involves choosing the packets to be sent based on something other than arrival time. The Active queue management is important subject to manage this queue to increase the effectiveness of Transmission Control Protocol networks. Active queue management (AQM) is an effective means to enhance congestion control, and to achieve trade-off between link utilization and delay. The de facto standard, Random Early Detection (RED), and many of its variants employ queue length as a congestion indicator to trigger packet dropping. One of these enhancements of RED is FRED or Fair Random Early Detection attempts to deal with a fundamental aspect of RED in that it imposes the same loss rate on all flows, regardless of their bandwidths. FRED also uses per-flow active accounting, and tracks the state of active flows. FRED protects fragile flows by deterministically accepting flows from low bandwidth connections and fixes several shortcomings of RED by computing queue length during both arrival and departure of the packet. Unlike FRED, we propose a new scheme that used hazard rate estimated packet dropping function in FRED. We call this new scheme Enhancement Fair Random Early Detection. The key idea is that, with EFRED Scheme change packet dropping function, to get packet dropping less than RED and other AQM algorithms like ARED, REM, RED, etc. Simulations demonstrate that EFRED achieves a more stable throughput and performs better than current active queue management algorithms due to decrease the packets loss percentage and lowest in queuing delay, end to end delay and delay variation (JITTER).
文摘This paper proposed an Integrated Random Early Detection(IRED)method that aims to resolve the problems of the queue-based AQM and loadbased AQM and gain the benefits of both using indicators from both types.The arrival factor(e.g.,arrival rate,queue and capacity)and the departure factors are used to estimate the congestion through two integrated indicators.The utilized indicators are mathematically calculated and integrated to gain unified and coherent congestion indicators.Besides,IRED is built based on a new dropping calculation approach that fits the utilized congestion indicators while maintaining the intended buffer management criteria,avoiding global synchronization and enhancing the performance.The results showed that IRED,compared to RED,BLUE,ERED,FLRED,EnRED and DcRED,decreased packet delay and loss under various network status.Specifically,the results showed that in heavy and moderate traffic,the proposed IRED method outperformed the state-of-the-art methods in loss and delay by 18% and 10.6%,respectively.
文摘为了提高响应流和非响应流之间的公平性,提出了一种基于速率公平的RED改进算法——RF-RED(ratefairness random early detection).该算法在路由器端计算UDP流的平均速率并与TCP友好流速率进行比较,根据比较结果动态调整UDP流和TCP流的最大丢包率,最后使用RED算法分别更新UDP流和TCP流的实际丢包率.通过使用RF-RED算法,UDP流在瓶颈链路上成为TCP友好流,同时瓶颈带宽得到了公平利用.仿真结果验证了该算法的有效性.
文摘针对随机早期检测(random early detection,RED)算法在慢速拒绝服务攻击(low-rate deny of serv-ice,LDoS)面前的脆弱性问题,本文通过对比路由器分别在RED和尾丢弃Drop-Tail算法管理下遭受LDoS攻击时的队列平均占用率及吞吐量,指出虽然路由器在RED算法下具有较大的空闲缓冲区,却不能对网络流量攻击起到缓冲作用.仿真对比实验表明,LDoS攻击使得路由器在RED下比Drop-Tail具有更大的链路损失带宽.指出现有LDoS的防范和检测方法的不足,构造了一种分布式LDoS攻击模型并给出一组模型实例,该模型说明现有突发流量检测方法不足以弥补RED脆弱性,也说明网络流量行为的关联复杂性.
文摘拥塞控制(congestion control)机制是确保InternetQoS的关键因素,随机早期检测(Random Early D etection,RED)算法是提高网络服务质量、解决网络阻塞的重要算法。针对网关的到达队列来说,丢包率的算法采用RED基本思想中与平均队列长度呈线性的关系并不合适,提出了立方RED算法。算法对RED算法进行了改进,使流丢包率与平均队列长度呈立方函数关系,通过NS-2仿真软件研究表明,算法可以有效的增加了网关的吞吐量、减少丢包率。
