The Asymmetric Best-Effort Service

We present Asymmetric Best-Effort, a novel service to provide a ``throughput versus delay jitter`` differentiated service for IP packets. With this service, every best effort packet is marked as either green or blue. Green packets, typically sent by real-time applications such as interactive audio, receive more losses during bouts of congestion than blue ones. In return, they receive less delay jitter. Both green and blue services are best-effort. The incentive to choose one or other is based on the nature of one`s traffic and on traffic conditions. If applications are TCP-friendly, an application sending blue packets will receive more throughput but also more delay jitter, than it would if it sent green packets for a given network state and path. Service provision at each cooperating router can be achieved by Packet Admission Control (PAC) and scheduling. We develop and simulate an initial algorithm that supports this service. It uses a modified version of RED for packet drop differention while scheduling of blue and green packets is facilated using Earliest Deadline First (EDF). These first results show the feasiblity of the service

A Proposal for an Asymmetric Best-Effort Service

We propose Asymmetric Best-Effort, a novel service to provide a throughput versus delay jitter differentiated service for IP packets. With this service, every best effort packet is marked as either Green or Blue. Green packets, typically sent by real-time appli- cations such asinteractive audio, receive more losses during bouts of congestion than Blue ones. In return, they receive less delay jitter. Both Green and Blue services are best-effort. The incentive to choose one or other is based on the nature of one`s traffic and on traffic conditions. If applications are TCP-friendly, those sending Blue packets will receive more throughput but also more delay jitter, than they would if they sent Green packets for a given network state and path

The Asymmetric Best-Effort Service

We present Asymmetric Best-Effort, a novel service to provide a ``throughput versus delay jitter'' differentiated service for IP packets. With this service, every best effort packet is marked as either green or blue. Green packets, typically sent by real-time applications such as interactive audio, receive more losses during bouts of congestion than blue ones. In return, they receive less delay jitter. Both green and blue services are best-effort. The incentive to choose one or other is based on the nature of one's traffic and on traffic conditions. If applications are TCP-friendly, an application sending blue packets will receive more throughput but also more delay jitter, than it would if it sent green packets for a given network state and path. Service provision at each cooperating router can achieved by Packet Admission Control (PAC) and scheduling. We develop and simulate an initial algorithm that supports this service. It uses a modified version of RED for packet drop differention while scheduling of blue and green packets is facilated using Earliest Deadline First (EDF). These first results show the feasiblity of the service

The Asymmetric Best-Effort Service

We present Asymmetric Best-Effort (ABE), a novel service to provide a throughput versus delay jitter service for IP packets. With this service, every best effort packet is marked as either Green or Blue. Green packets, typically sent by real-time applications such as interactive audio, receive more losses during bouts of congestion than Blue ones. In return, they receive a smaller bounded queueing delay. Both Green and Blue services are best-effort. The incentive to choose one or other is based on the nature of one`s traffic and on traffic conditions. If applications are TCP-friendly, an application sending Blue packets will receive more throughput but also more delay jitter, than it would if it sent Green packets for a given network state and path. Service provision at each co-operating router can be achieved by Packet Admission Control (PAC)and scheduling. We develop and simulate an initial lgorithm that supports this service whose first results show the feasibility of the service

The Alternative Best-Effort Service

Alternative Best-Effort (ABE) is a novel service for IP networks which offers applications the choice between receiving a lower end-to-end delay and receiving more overall throughput. Every best effort packet is marked as either green or blue. Green packets receive a low, bounded queueing delay. To ensure blue packets do not suffer as a result, green flows receive less throughput during bouts of congestion. The unique combination of lower delay with reduced throughput for green makes it different from recent differentiated service proposals such as expedited forwarding and assured forwarding. The incentive to choose one or other is based on the nature of one's traffic and on traffic conditions. Typically, green flows have real-time deadlines (e.g. interactive audio), while blue traffic (e.g. bulk data transfer) seeks to minimise overall transfer time. There is benefit for all traffic in that green traffic achieves a low delay and blue traffic will receive at least as much throughput as it would in a flat best-effort network and usually more. Neither traffic type can be said to be better, thus flat rate pricing may be maintained, and there is no need for reservations or profiles. We first describe the ABE service. We then describe and simulate a first generation router implementation. It combines packet drop differentiation with differential scheduling for blue and green packets. Green packets have a fixed bounded delay. Differential dropping is done by ensuring blue flows are compensated for the increased delay by higher throughput. Given these constraints, the parameters of the system are regulated to minimise green losses. Simulations show that our implementation is able to implement the definition of the ABE service

Downlink scheduling and resource management for best effort service

Abstract. Throughput performance and geographical service fairness of best effort service used for downlink of a 802.16e based TDD-OFDMA sectored cellular networks are evaluated in conjunction with different scheduling schemes and frequency reuse plans. The OFDM systems are based on two multiple access schemes, which are the OFDM-TDM and OFDMA, and considered scheduling schemes are round robin, max C/I, PF and G-fair schedulers with adaptive rate control. The 3-sectored 1 FA, 3-sectored 3 FA, and 6-sectored 3 FA plans are compared in terms of throughput, capacity, and geographical service fairness, which assist in determining the choice of a scheduling and frequency reuse plan

Quality of service assurance for the next generation Internet

The provisioning for multimedia applications has been of increasing interest among researchers and Internet Service Providers. Through the migration from resource-based to service-driven networks, it has become evident that the Internet model should be enhanced to provide support for a variety of differentiated services that match applications and customer requirements, and not stay limited under the flat best-effort service that is currently provided. In this paper, we describe and critically appraise the major achievements of the efforts to introduce Quality of Service (QoS) assurance and provisioning within the Internet model. We then propose a research path for the creation of a network services management architecture, through which we can move towards a QoS-enabled network environment, offering support for a variety of different services, based on traffic characteristics and user expectations

ABE: providing a low-delay service within best effort

Alternative best effort (ABE) is a novel service for IP networks, which relies on the idea of providing low delay at the expense of possibly less throughput. The objective is to retain the simplicity of the original Internet single-class best-effort service while providing low delay to interactive adaptive applications

Quality of service support in differentiated services packet networks

During the past few years, new types of Internet applications which require performance beyond the best-effort service that is provided by the current Internet have emerged. These applications include the transmission of voice and video, which require a fixed end-to-end delay bound in order for the end-user to perceive an acceptable level of service quality. The Differentiated Services (Diffserv) model has been proposed recently to enhance the traditional best-effort service, and provide certain Quality of Serviee (QoS) guarantees to these applications. Its current definition, however, does not allow for a high level of flexibility or assurance and, therefore, it can not be widely deployed. In this paper, we introduce a new protocol for a Diffserv architecture which provides a simple and efficient solution to the above problem. It is a complete protocol, in the sense that it deals with the issues of packet scheduling, admission control, and congestion control. We will show, through experimental results, that our proposed protocol can improve the flexibility and assurance provided by current solutions, while maintaining a high level of network utilization.published_or_final_versio