TCP throughput guarantee in the DiffServ Assured Forwarding service: what about the results?

Since the proposition of Quality of Service architectures by the IETF, the interaction between TCP and the QoS services has been intensively studied. This paper proposes to look forward to the results obtained in terms of TCP throughput guarantee in the DiffServ Assured Forwarding (DiffServ/AF) service and to present an overview of the different proposals to solve the problem. It has been demonstrated that the standardized IETF DiffServ conditioners such as the token bucket color marker and the time sliding window color maker were not good TCP traffic descriptors. Starting with this point, several propositions have been made and most of them presents new marking schemes in order to replace or improve the traditional token bucket color marker. The main problem is that TCP congestion control is not designed to work with the AF service. Indeed, both mechanisms are antagonists. TCP has the property to share in a fair manner the bottleneck bandwidth between flows while DiffServ network provides a level of service controllable and predictable. In this paper, we build a classification of all the propositions made during these last years and compare them. As a result, we will see that these conditioning schemes can be separated in three sets of action level and that the conditioning at the network edge level is the most accepted one. We conclude that the problem is still unsolved and that TCP, conditioned or not conditioned, remains inappropriate to the DiffServ/AF service

An Ontology for Network Services

Most of the network service specifications are implemented using relational databases or XML schemas. However, those specifications are not flexible and expressive enough to be extended with new service classes, different corporate policies, network configurations and deployment strategies; thus, most of the QoS management operations are implemented as hard-coded software components. This paper presents a novel approach in the specification of IP network services, using F-logic knowledge representation framework, aiming to include, in the same specification, the high-level service requirements, the network model and the necessary operations for the deployment of multiple network services

XML service level specification and validation

This paper addresses the problem of formalizing Service Level Specifications (SLSs) as a first step to simplify and automate the configuration and management of multiservice IP networks. A formal representation of SLSs will allow their automatic validation and processing, fostering the dynamic negotiation of SLSs and the interoperability among service management entities. In this way, taking advantage of XML extensibility and portability, a Schema is presented describing XML SLSs sections and their contents. In addition, an XML validator tool was built to check if SLSs are correctly specified. An XML SLS for an IP telephony service is used to exemplify this proposal expressiveness

Performance isolation for network slices in Industry 4.0: The 5Growth approach

Network slicing plays a key role in the 5G ecosystem for verticals to introduce new use cases in the industrial sector, i.e., Industry 4.0. However, a widely recognized challenge of network slicing is to provide traffic isolation and concurrently satisfy diverse performance requirements, e.g., bandwidth and latency. Such challenge becomes even more important when serving a large number of network traffic flows under a resource-limited condition between distributed sites, e.g., factory floor and remote office. In this work, we present the capability to retain these two goals at the same time, by applying the virtual queue notion over a priority queuing based pipeline in P4 switch over software-defined networks. To examine the effectiveness of our approach, a proof-of-concept is setup to serve different requests of Industry 4.0 use cases over a mixed data path, including P4 switch and Open vSwitch, for a large number of network flows.This work was supported in part by the EU H2020 5GROWTH Project under Grant 856709

Quality of services for remote control in High Energy Physics experiments: a case study

Abstract The development of new advanced applications and the evolution in networking are two related processes which greatly benefit from two-way exchanges and from progress in both fields. In this study we show how mission-oriented networked applications can be effectively deployed for research purposes if coupled to the support of Quality of Service (QoS) in IP networks. QoS is one of the latest research topics in network engineering. In this article we focus on two specific examples of networked applications: remote instrumentation control and remote display of analysis data when applied for the support of experiments in the high energy physics field. In this paper we focus on the application requirements: the availability of a reliable transmission channel, limited one-way delay for timely interactions between servers and clients and fairness in network resources allocation in case of contention. The above-mentioned requirements can be addressed through the support of QoS, i.e. through the differential treatment of packets on the end-to-end data path. Several technologies and protocols for QoS support in packet networks have been devised during the last years by the research community. In this study we focus on the Differentiated Services (diffserv) approach, an architecture characterized by high scalability, flexibility and interoperability. In this paper we identify the application requirements and we quantitatively specify the corresponding service profiles. The diffserv network architecture needed to support the services is defined in terms of functional blocks (policing, classification, marking and scheduling) and of their placement in the network. Finally, for each of them the configuration best suited to remote control support is defined

Análisis de las prestaciones del acondicionador de tráfico CBM en un dominio DiffServ

The Counters-Based Modified (CBM) traffic conditioner was introduced in a previous work as a feasible option to implement the Assured Forwarding (AF) service in DiffServ. In this paper we present an end-to-end performance analysis of TCP Reno sources that employ the CBM in a DiffServ domain. We present simulation results in a three-RIO-node topology under miscellaneous characteristics: different contract rates, heterogeneous RTT, co-existance of best-effort and AF sources, and eficience of CBM when some network node does not implement service differentiation. As shown in simulation results, it is possible to guarantee an AF service that ensures contracted target rates and performs a fair share of the excess bandwidth.Este trabajo se enmarca dentro del proyecto CICYT FAR-IP (TIC2000-1734-C03-03)

Plataforma de configuração e monitorização de QoS numa rede diffserv

À medida que surgem novas aplicações cada vez mais complexas e exigentes, torna-se necessário dar um tratamento diferenciado ao tráfego que circula na Internet prestando uma qualidade de serviço (QoS) de rede apropriada. Neste artigo, inserido na área de monitorização de QoS em redes IP, propõe-se uma plataforma de configuração e monitorização de QoS integrada na ferramenta de simulação Network Simulator (NS) que permite parametrizar e testar vários mecanismos presentes numa rede de Serviços Diferenciados (DiffServ). Os resultados das principais métricas de QoS, fornecidas pela aplicação sob a forma de tabelas, gráficos e de uma visualização on-line, tornam possível reajustar e corrigir os valores de parametrização dos diversos mecanismos e melhorar o desempenho global da rede DiffServ numa perspectiva fim-a-fim

Comparaçao de plataformas para suporte de serviços diferenciados em redes IP

O principal objectivo deste trabalho é fazer a comparação, de um ponto de vista prático, de duas plataformas para o suporte de Serviços Diferenciados em redes IP: uma desenvolvida pelo ICA/EPFL para plataformas Linux, e a outra baseada em routers Cisco. Para além de comparar e estabelecer as estratégias de configuração em cada plataforma, funcionalidades Diffserv como a classificação, condicionamento de tráfego ou queuing, são testadas, avaliadas e discutidas. Particularmente, são testadas possíveis implementações dos PHBs EF, AFs e BE. As capacidades de oferecer largura de banda garantida, prioritização de tráfego, ou mecanismos adequados de condicionamento de tráfego são avaliadas, assim como o impacto que o tráfego de background tem no atraso dos pacotes de prioridade mais alta. A utilização extra do CPU provocada pelas funcionalidades Diffserv nos routers é também avaliada.EURESCOM P1006 / DISCMAN