Weighted fairness guarantee for scalable DiffServ assured forwarding (original) (raw)
Related papers
Weighted fair bandwidth sharing using SCALE technique
Computer Communications, 2001
Currently there is not enough work on the Internet weighted fair bandwidth sharing without per-flow management, especially when both UDP and TCP flows of different RTTs and different bandwidth targets coexist. This paper contains two contributions: 1) A mechanism called SCALE-WFS, Scalable Core with Aggregation Level labEling-Weighted Fair bandwidth-Sharing, is presented to achieve near-optimal Max-Min weighted fairness without per-flow management at core routers, in the context of differentiated service networks. Through extensive simulation and simple analysis, we show the performance problems with current solutions and propose SCALE-WFS to solve these problems. This scheme works effectively for different flow weights, RTTs, protocols (TCP and UDP), under the scenarios of different bandwidth provisioning and multiple congested gateways, all of which we consider the basic requirements for a practical solution. 2) Apart from "per-flow" and completely "core-stateless", SCALE represents a third management level-the label-based flow "aggregation" level. It reduces the information redundancy in the "per-flow" and surpasses the performance of the "core-stateless". This is important to differentiated service networks where we try to avoid the non-scalability of per-flow management while keeping its good Quality of Services. In this paper, we show that SCALE-WFS is effective and scalable, robust and extensible.
A fair bandwidth distribution mechanism in a Diffserv network
Computer Communications, 2007
Previous works for the Assured Forwarding (AF) service in a Diffserv network have no sufficient consideration on the target rate and the effect of RTT and UDP in achieving the fairness of bandwidth share. Also previous works act like Best-effort service in an Under-Provisioned Network (UPN) condition. In this paper, in order to solve these problems, we propose the Proportionally Fair Differentiated Service Architecture (PFDSA), which is composed of tcp-microflow based Target rate and RTT Aware Three Color Marker (tmTRA3CM), udp-microflow based Three Color Marker (um3CM), Target Rate Based Dropper (TRBD), and Target Rate Adjusting Function (TRAF). In the results of comparisons on the performance among existing mechanisms and the PFDSA in the OPN (Over-Provisioned Network) and the UPN conditions, the PFDSA was able to further mitigate the RTT and UDP effects than the previous works. The PFDSA was shown to provide better fair bandwidth distribution proportional to various target rates even in the UPN condition.
Core-stateless proportional fair queuing for AF traffic
IEEE Global Telecommunications Conference, 2004. GLOBECOM '04.
Proportional fair queuing is to ensure that a flow passing through the network only consumes a fair share of the network resource that is proportional to its committed rate or other service level agreement (SLA). It is of great importance in differentiated services (DiffServ) networks as well as other price incentive network services. In this paper, we propose a simple core-stateless proportional fair queuing algorithm (CSPFQ) for the assured forward (AF) traffic in DiffServ networks. We first develop our algorithm based on a fluid model analysis and then extend it to a realizable packet level algorithm. We prove analytically and instantiate through simulations that our algorithm can achieve proportional fair bandwidth allocation among competing flows without requiring routers to estimate flows' fair share rates. Our simulation results also demonstrate that our algorithm outperforms the weighted core-stateless fair queuing (WCSFQ) in terms of proportional fairness.
Refined assured forwarding framework for differentiated services architecture
Computer Communications, 2007
This paper presents a new refined assured forwarding (RAF) framework for improving the performance of DiffServ architecture where heterogeneous traffic flows share the same aggregate class. The new framework requires minimal modification to existing DiffServ routers by adding a second layer of classification of flows based on their average packet sizes and using Weighted Fair Queueing for flow scheduling. The efficiency of the new architecture in enhancing the performance of DiffServ is demonstrated by simulation results for delay, packet delivery, throughput, and packet loss, under different traffic scenarios.
IEEE/ACM Transactions on Networking, 2003
Router mechanisms designed to achieve fair bandwidth allocations, like Fair Queueing, have many desirable properties for congestion control in the Internet. However, such mechanisms usually need to maintain state, manage buffers, and/or perform packet scheduling on a per flow basis, and this complexity may prevent them from being cost-effectively implemented and widely deployed. In this paper, we propose an architecture that significantly reduces this implementation complexity yet still achieves approximately fair bandwidth allocations. We apply this approach to an island of routers -that is, a contiguous region of the network -and we distinguish between edge routers and core routers. Edge routers maintain per flow state; they estimate the incoming rate of each flow and insert a label into each packet header based on this estimate. Core routers maintain no per flow state; they use FIFO packet scheduling augmented by a probabilistic dropping algorithm that uses the packet labels and an estimate of the aggregate traffic at the router. We call the scheme Core-Stateless Fair Queueing. We present simulations and analysis on the performance of this approach.
Improving fairness in a WRED-based DiffServ network: A fluid-flow approach
Performance Evaluation, 2008
The DiffServ architecture has been proposed as a scalable approach for upgrading the Internet, adding service differentiation functionalities. However, several aspects of this architecture still have to be analyzed and solved. For this reason, network designers need to be provided with tools which are able to estimate the average behavior of a DiffServ network with a high level of accuracy and in a short time. In this paper a fluid-flow model of a DiffServ network supporting Assured Forwarding Per-Hop Behavior (PHB) and loaded with TCP flows is proposed. At the edge of the network, two rate three color markers (TRTCM) are employed as profile meters, while within the network core routers implement a Weighted RED (WRED) buffer management mechanism. In order to demonstrate the high accuracy of the proposed model, a comparison between model and simulation results is performed, taking into account not just a bottleneck link, but a complex network topology. The proposed analytical framework is then used to analyze the impact of several factors on the fair sharing of network resources between traffic aggregates with the same traffic profile, and to achieve some guidelines for WRED parameter settings with the aim of reducing unfairness.
Proportional bandwidth allocation in diffserv networks
IEEE INFOCOM 2004, 2004
By analyzing the steady state throughput of TCP flows in differentiated service (DiffServ) networks, we show that current DiffServ networks are biased in favor of those flows that have a smaller target rate, which results in unfair bandwidth allocation. In order to solve this unfairness problem, we propose an adaptive marking scheme, which allocates bandwidth in a manner which is proportional to the target rates of the aggregate TCP flows in the DiffServ network. This scheme adjusts the target rate according to the congestion level of the network, so that the aggregate flow can obtain its fair share of the bandwidth. Since it utilizes edge-to-edge feedback information without measuring or keeping any per-flow state, this scheme is scalable and does not require any additional signaling protocol or any significant changes to the current TCP/IP protocol. It can be implemented in a distributed manner using only two-bit feedback information, which is carried in the TCP acknowledgement. Using extensive simulations, we show that the proposed scheme can provide each aggregate flow with its fair share of the bandwidth, which is proportional to the target rate, under various network conditions.
Link-Based Fair Aggregation: A Simple Approach to Scalable Support of Per-Flow Service Guarantees
To support service guarantees in packet-switched networks, three approaches have been proposed. They are the Stateless Core (SCORE) approach, the Integrated Services (IntServ) approach, and the Differentiated Services (DiffServ) approach. The granularities of service guarantees provided by these approaches at each router are respectively packet level, flow level, and class level. In this paper, we propose a novel approach, called Link-Based Fair Aggregation (LBFA) approach to scal- able support of service guarantees. While the granularity of service guar- antees supported by LBFA is link level at each router, we show through analysis that the proposed LBFA approach can achieve as good as or even better per-flow service guarantees than the current three approaches.
An enhanced algorithm for fair traffic conditioning in Differentiated Services networks
2004
Fair bandwidth sharing among traffic flows with different characteristics in Differentiated Service (DiffServ) networks is the focus of the current research. This paper examines and enhances an algorithm developed to enforce fairness among disparate TCP flows in the assured forwarding (AF) service in DiffServ. equation based marking (EBM) was introduced (M. El-Gendy and K. Shin (2002)) to enforce fairness in AF by monitoring existing network conditions used in marking decisions. The estimation of packet losses by the algorithm is integral to marking. The loss rates of different connections were demonstrated to converge hence enforcing a fair marking regardless of the metrics of individual flows. In this paper, EBM is analyzed for fairness and enhanced by implementing a more efficient technique for loss rate estimation. Comparison is made between EBM and the enhanced technique with results showing appreciable improvements in the maintenance of fairness. Furthermore, a service definition required by QoS standards is met with the implementation of the additional algorithm to EBM.