Effort Internet Research Articles

ARCH: A dual‐mode fairness‐driven AQM for promoting cooperative behaviour in best effort Internet

The cooperative behaviour of end-systems in efficiently and fairly utilizing the scarce bandwidth is of paramount significance in the best effort Internet. Not only does the uncooperative behaviour result in unfairness, but it may also induce congestion collapse. How to urge end-systems to share the bandwidth cooperatively is a problem that depends, in essence, on incentives. This study presents a novel fairness-driven active queue management (AQM)-based incentive scheme to detect and take punitive action against any uncooperative behaviour. Different from all other fairness-driven AQM schemes, the proposed scheme offers a dual-mode control function that can adaptively switch between stateless and partial-state modes in order to be scalable. The control function remains stateless at low to moderate congestion levels and maintains a partial-state when congestion becomes severe. In the stateless mode, the identification and restriction of unresponsive flows are based on a matched-drop mechanism having a dynamic drawing factor to differentially drop packets from unresponsive flows. In the partial-state mode, a fair-share is estimated and flows whose arrival rates exceed the fair-share bandwidth get their rates limited to the fair rate. Simulation results demonstrate the reasonable performance improvement of the proposed scheme over well-known fairness-driven AQM schemes.

End-to-End Time-Sensitive Optical Networking: Challenges and Solutions

Time-sensitive applications, most notably, for 5G fronthauling and Industry 4.0, require deterministic (jitter-free) low-latency, highly reactive, and trustable networks, as opposed to today's best effort Internet. We review existing solutions, both established and at the research stage, and compare them for key next-generation 5G fronthauling and industrial requirements.

Supporting consumer services in a deterministic industrial internet core network

A convergence is occurring in the networking world. Industrial networks currently provide deterministic services in robotic factories and aircraft, while the best effort Internet of Things provides best effort services for consumers. We argue that a convergence should occur, and that a future converged Industrial Internet of Things (IIoT) should support both best effort and deterministic services, with very low latency and jitter. This article presents the design of a deterministic IIoT core network consisting of many simple deterministic packet switches configured by an SDN control plane. The use of deterministic communications can reduce router buffer sizes by a factor of ≥ 1000, and can reduce end-to-end latencies to the speed of light in fiber. A speed-of-light deterministic core network can have a profound impact on virtually all consumer services such as multimedia distribution, e-Commerce, and cloud computing or gaming systems. Highly aggregated video streams can be delivered over a deterministic virtual network with very high link utilization (≤ 100 percent), very low packet jitter (≤ 10 μs), and zero congestion. In addition to improving consumer services, a converged deterministic IIoT core network can save billions of dollars per year as a result of significantly improved network utilization and energy efficiency.

Risk-balanced dimensioning and pricing of End-to-End differentiated services

End-to-End (E2E) differentiated services refer to information services, delivered over the modern Internet with a differentiated grade of Quality of Service (QoS) over heterogeneous networks. Such services represent a prospective way of satisfying the needs of demanding customers, which cannot be satisfied with QoS delivered by the usual best effort Internet connectivity. This paper focuses on the differentiation aspect and develops stochastic optimization models designed for the selection of a portfolio of services with varying degrees of QoS by a risk-averse service provider under uncertainty concerning demand, generated by a multi-segment market of heterogeneous users.The model includes decisions concerning service offer, quality of services, pricing and network capacity expansion. The risk/profit trade-off is computed using an industry-specific risk measure, which is the fraction of demand not satisfied under the required QoS. We provide the evaluation of a plausible stepwise business strategy for the introduction of these services

QoS routing algorithm with multi-dimensions for overlay networks

Overlay networks have emerged as a useful approach to providing a general framework for new applications and services that are to be implemented without significantly changing the IP-layer network infrastructure. Overlay routing has been used as an alternative to the default best effort Internet routing for the absence of end-to-end Quality of Service (QoS). While the former has recently been investigated, the conflict of QoS restraints and resource optimization remains unsolved. Recent studies have shown that overlay paths can give better latency, loss rate and TCP throughput. In this paper, a multi-dimensional QoS objective model based on the analysis of multiple QoS constraints has been presented, and a routing algorithm to optimise the overlay resource of its nodes and links is then proposed. In fact, the algorithm obtained multiple QoS values using probability theory to achieve the routing according to the multi-dimensional QoS objective vector of the QoS objective model. Simulation results reveals that the algorithm works better than other existing algorithms in balancing the network resources, and applications with stringent QoS requirements could be run.

Evalvid-RA: trace driven simulation of rate adaptive MPEG-4 VBR video

Due to the increasing deployment of conversational real-time applications like VoIP and videoconferencing, the Internet is today facing new challenges. Low end-to-end delay is a vital QoS requirement for these applications, and the best effort Internet architecture does not support this natively. The delay and packet loss statistics are directly coupled to the aggregated traffic characteristics when link utilization is close to saturation. In order to investigate the behavior and quality of such applications under heavy network load, it is therefore necessary to create genuine traffic patterns. Trace files of real compressed video and audio are text files containing the number of bytes per video and audio frame. These can serve as material to construct mathematical traffic models. They can also serve as traffic generators in network simulators since they determine the packet sizes and their time schedule. However, to inspect perceived quality, the compressed binary content is needed to ensure decoding of received media. The EvalVid streaming video tool-set enables this using a sophisticated reassembly engine. Nevertheless, there has been a lack of research solutions for rate adaptive media content. The Internet community fears a congestion collapse if the usage of non-adaptive media content continues to grow. This paper presents a solution named Evalvid-RA for the simulation of true rate adaptive video. The solution generates real rate adaptive MPEG-4 streaming traffic, using the quantizer scale for adjusting the sending rate. A feedback based VBR rate controller is used at simulation time, supporting TFRC and a proprietary congestion control system named P-AQM. Example ns-2 simulations of TFRC and P-AQM demonstrate Evalvid-RA's capabilities in performing close-to-true rate adaptive codec operation with low complexity to enable the simulation of large networks with many adaptive media sources on a single computer.

Seamless Failure Recovery for Real-time Multimedia Applications in MPLS Networks

The QoS provided by current best effort Internet is not good enough for real-time multimedia applications that are categorized as premium traffic. It is believed that QoS guarantees could be better provided by the connection oriented networks. Multi Protocol Label Switching (MPLS) is one such technology and these connection oriented networks are inherently more prone to network failures. Re-routing is a solution to cope with them. However, the re-routing always causes packet losses and results in service outage. Therefore, the QoS of the real-time premium traffic is highly degraded. The seamless failure recovery proposed in this paper can be used for real-time premium traffic that needs a guaranteed QoS. It applies an FEC technique to the conventional re-routing based path protection and seamlessly recovers the packet losses due to re-routing by way of an FEC recovery technique. The numerical and simulation results show that the proposed method can provide network architecture without service outage for real-time premium traffic while minimizing the service costs such as redundant traffic and additional buffer at edge routers.

Concept of Virtual Path Hopping to Improve QoS and Reliability of Connection-oriented Networks

The QoS provided by today's best effort Internet is not good enough for real-time premium traffic. It is believed that the QoS guarantees of the Internet could be better provided by connection-oriented networks. IP/MPLS is one such technology and these connection-oriented networks are inherently more vulnerable to network failures. Network failures can broadly be classified into two types, ie., link/path and degraded failures. Degraded failures that account for about 50% of total failures are detected by control-plane timers. The control plane and the data plane of IP/MPLS networks are logically separated and therefore a failure in the control plane should not immediately terminate communications on the data plane. The Virtual Path Hopping (VPH) concept proposed in this study distinguishes these degraded failures from link/path failures and avoids the terminations of data communications on the data plane that are due to these degraded failures. It changes the traffic carrying a degraded VP to a new VP in a predetermined VP-pool before the control-plane timer expires due to degraded failure. This paper discusses the concept of VPH and its numerous advantages such as load balancing, traffic distribution, and the ability to support dual-failure situations. Computer simulations were conducted and the results are presented to support the concept of VPH.

A connection-oriented network architecture with guaranteed QoS for future real-time applications over the Internet

The QoS provided by today’s best effort Internet is not good enough, especially for real-time interactive traffic categorized as Premium Traffic (PT). It is believed that QoS guarantees could be better provided by connection-oriented networks such as IP/MPLS. However, these connection-oriented networks are inherently more prone to network failures. Failures of connection-oriented MPLS can be broadly classified into two types namely: link/path failures and degraded failures. Degraded failures that account for about 50% of total failures are detected by the timers maintained at the control plane peers. The control plane and the data plane of IP/MPLS packet networks are logically separated and therefore a failure in the control plane should not immediately disconnect the communications in the data plane. The Virtual Path Hopping (VPH) concept in this study distinguishes these two types of failures and avoids the disconnections of communications in the data plane due to degraded failures. Thereby it reduces the number of failures in the data plane. Computer simulations were performed and the results indicate that VPH is a proactive technique that minimizes failures in the data plane. The proposed Dynamic Virtual Path Allocation (DVPA) algorithm improves the availability of the connection-oriented networks by overcoming link/path failures, especially for PT, without compromising the network resource utilization efficiency. Comprehensive simulations were performed to evaluate the DVPA algorithm and the results show the improvements that DVPA can achieve. Therefore implementation of the DVPA algorithm in conjunction with VPH would improve the reliability and availability aspects of QoS in connection-oriented IP/MPLS packet networks.

Peer-to-Peer Based Multimedia Distribution Service

Recently, there are many research interests in providing efficient and scalable multimedia distribution service. However, stringent quality-of-service (QoS) requirements for media distribution, as well as dynamically changing and heterogeneous network capacity in today's best effort Internet, bring many challenges. In this paper, we introduce a novel framework for multimedia distribution service based on peer-to-peer (P2P) networks. A topology-aware overlay is proposed in which hosts self-organize into groups. End hosts within the same group have similar network conditions and can easily collaborate with each other to achieve QoS awareness. In order to improve media delivery quality and provide high service availability, we further propose two distributed heuristic replication strategies, intergroup replication and intragroup replication, based on this topology-aware overlay. Specifically, intergroup replication is aimed to improve the efficiency of media content delivery between the group where a request is issued and the group where the content is stored. Also, intragroup replication is targeted at improving the availability of the content. Extensive simulation results show that the latency in our proposed architecture is 20% less than that of the FreeNet and 50% less than that of the randomly replication system. Simulation results also show that the video quality in our system is much better than that in the other two systems. Our P2P-based approach is also distributed, scalable, cost effective, and aware of the performance.

QoS in DSL access

Which enrichments are required for the DSL architecture to transform the DSL access network from a vehicle for best effort Internet access to a multiservice platform enabling added value conversational and data services? This article details an architecture for DSL access facilitating IP service guarantees leveraging the available QoS mechanisms in the transport-technology-specific data plane, while extending the control plane. Enhanced resource and information control, policy enforcement, and advanced IP connection establishment mechanisms are key elements for the network access provider to enter the value chain for delivery of IP services.

Multirate video multicast over the Internet: an overview

Multirate multicast is an effective method for video distribution to a set of heterogeneous receivers. We present a comprehensive survey on multirate video multicast over the best effort Internet. We first review the key techniques in video encoding and network transport, and describe the representative approaches. We then study various trade-offs based on some important design issues and performance criteria, such as bandwidth economy, adaptation granularity, and coding complexity. Finally, we present some ongoing work and discuss possible avenues for future research.

The incremental deployability of RTT-based congestion avoidance for high speed TCP Internet connections

Our research focuses on end-to-end congestion avoidance algorithms that use round trip time (RTT) fluctuations as an indicator of the level of network congestion. The algorithms are referred to as delay-based congestion avoidance or DCA. Due to the economics associated with deploying change within an existing network, we are interested in an incrementally deployable enhancement to the TCP/Reno protocol. For instance, TCP/Vegas, a DCA algorithm, has been proposed as an incremental enhancement. Requiring relatively minor modifications to a TCP sender, TCP/Vegas has been shown to increase end-to-end TCP throughput primarily by avoiding packet loss. We study DCA in today's best effort Internet where IP switches are subject to thousands of TCP flows resulting in congestion with time scales that span orders of magnitude. Our results suggest that RTT-based congestion avoidance may not be reliably incrementally deployed in this environment. Through extensive measurement and simulation, we find that when TCP/DCA (i.e., a TCP/Reno sender that is extended with DCA) is deployed over a high speed Internet path, the flow generally experiences degraded throughput compared to an unmodified TCP/Reno flow. We show (1) that the congestion information contained in RTT samples is not sufficient to predict packet loss reliably and (2) that the congestion avoidance in response to delay increase has minimal impact on the congestion level over the path when the total DCA traffic at the bottleneck consumes less than 10% of the bottleneck bandwidth.

Delay performance analysis of the new Internet services with guaranteed QoS

In addition to the traditional best effort Internet protocol (IP) service of the Internet, the Internet Engineering Task Force has defined two new services that provide quality of service guarantees on throughput and delay. In this paper, we analyze the delay performance that can be achieved with the service that provides the most firm guarantees-the guaranteed quality of service. Using a voice and a video application as examples, the end-to-end delay is calculated. Three different scenarios are presented: local, regional, and long distance, differing in the distance covered and the number of IP routers traversed. It is shown that even in the long-distance case, the achievable end-to-end delay for the guaranteed service can be kept sufficiently low to support interactive applications with strict delay requirements. It is concluded that for low-rate applications, the efficiency cannot be higher than about 60-75%. For connections traversing a large number of routers, the variable delay as advertised by the routers is much higher than the expected delay. The second new service, called the controlled-load network element service, provides less firm delay guarantees. The end-to-end delay for this service is estimated using similar techniques. The results suggest that this service is suitable for interactive applications in the local and regional scenarios only. For the long distance scenario, the end-to-end delay is expected to be below 300 ms.