IP QoS Research Articles

A New IP Multicast QoS Model for Real-Time Audio/ Video Traffics on the IP Based Networks.(Dept.E)

On congested links/routers, Best-Effort delivery will seriously degrade the service provided to the real-time traffic. Real-time audio/video traffics could not depend on the Best-Effort delivery of datagrams, and therefore, like the Differentiated-services (Diffserv) Model, there is a need for a model that can give a per-flow service assurances. This paper discusses issues related to real-time audio/video applications requirements, the trade off between them and the network resources requirements. This p aper also states the IP QoS proposed models and presents a comparison between them. Finally, it describes in details the new proposed model which provides end-to-end performance guarantees to support the real-time audio/video traffics on the IP based networks. The new proposed model relies on having an acceptable delay, packet loss, and MTU (Maximum Transfer Unit). It also has an acceptable consumed bandwidth and buffers specially at the core routers in which the congestion usually occurs.

Enhanced packet routing queuing model in optical burst switching network using queue-based dynamic optical route scheduling

Optical Burst Switching (OBS) for all future optical network technology signatures. In OBS, the IP packet is known as a large explosion of data that is assembled in the input packets. The pre-assembly burst is sent to its intended location for offset time. It has shown that there are some security issues, but they do not resolve the node's ability to separate them. When they have suffered great losses to ensure that they are indispensable. If they are not safe, it may not waste resources on the optimal path.Current communication paradigms such as broadcast and multicast. Therefore, in optical networks, it is necessary to support these paradigms. Implementation of IP QoS policies does not apply to Optical Burst Switching (OBS) networks. These QoS requirements include controversy, optical signal quality, reliability, and delay.This work recommends the use of shared encryption for secure message traffic on OBS networks. The information is divided into as many strands as possible, and then it transmits at different times between pair of nodes and the different paths or routes. The proposed method to analyze the three strategies likely traffic analysis and route scheduling, packet header analysis,and authentication key verification.This proposed method,Queue-Based Dynamic Optical Route Scheduling (QDORS), provides flexible and efficient integrated packet-based traffic in OBS functions and Internet-based networks. It considered exploding a valid huge amount of data plans to reduce better channel usage, higher efficiency, and blocking probability.

Improving the Communication Performance in Multi-Agent Systems for Distributed Manufacturing Process Control

The distributed control of complex and dynamic manufacturing systems is a challenging task and the multi-agent system (MAS) becomes a suitable solution due to its flexibility in both distributing and integrating software functionalities across the controlled system. This paper investigates the potentials of improving agent message delivery by enhancing the underlying communication network with IP QoS mechanisms using service differentiation and early congestion avoidance techniques. The extensive simulation experiments demonstrated the effectiveness of our approach in providing small latency, small jitter and improved throughputs in ACL message delivery, whilst without deteriorating other data applications between distributed controllers.

Quality of Service over Heterogeneous Network with MPLS Backbone

Internet growth in recent years has encouraged many new applications to be provided for the end user. However, providing and maintaining high quality of service for these new applications is a challenging matter that is getting the attention of many many researchers nowadays. The QoS challenge is emanating from the diversity of these applications, in term of bandwidth requirements and high sensitivity to delay and delay variation. Three main architectures were proposed by IETF in an effort to make the IP QoS a reality. They are integrated services (Intserv), differentiated services (DiffServ) and multiprotocol label switching (MPLS). Sometimes perceived as competitor, these architectures are in fact complementary developments that approach the QoS challenge from different network perspectives. Thus these approaches can work together in a manner that provides a global QoS within Heterogeneous network. This paper aims to propose and discusses an improved admission control mechanism in order to achieve a global QoS in the HN Network. The proposed mechanism uses MPLS-TE tunnels at the core of Heterogeneous networks to maintain QoS for inter-domain flows and applications.

Performance Evaluation of Signaling in the IP QoS System

The IP QoS System is based on next generation networks (NGN) and differentiated services (DiffServ) architectures. Its main part is a signaling system, which allows to send a request from a user to the system for establishing new connection with predefined quality of service assurance. In this paper we present trial results of the proposed signalling system. The experiments were performed to measure setup delay utilizing artificial call generator/analyzer. To obtain results we assumed different distributions of interarrival and call holding times based on the literature. The results show that the setup delay strongly depends on access time to network devices, however also on the assumed call holding time models.

PaperOn Dimensioning and Routingin the IP QoS System

This article presents dimensioning and routing so-lutions in IP QoS System designed during the implementa-tion of the PBZ project: “Next Generation Services and Net-works – technical, application and market aspects: Trafficmanagement – IP QoS System”. The paper presents the func-tional architecture together to the description of the functionsand methods implemented in the system.

The Realization of the IP QoS Based on Network Processor

IP network unprecedented develops in the end of the last century and it evolutes to the next generation network. The network service also presents the characteristics of diversification. Thus the traditional real-time services have not already meet people's need. Algorithms proposed in this paper are developed based on network processor IXP2400 and SDK3.1, and observed on advanced router. Measured results show that, ACL processing module realizes filter and classification functions in the QoS model and meet the requirements filter and classification in QoS system.

Performance Improvement of video based applications in WFQ using Committed Access Rate

ABSTRACT In this paper, the video received, IP drop in WFQ is improved using committed access rate (CAR). The committed access rate is used for video and http applications and for WFQ queuing scheme. From results, it has been analyzed that the video received in WFQ shows much better improvement than the conventional. The significant results have been investigated for IP drop in case of WFQ with committed access rate and conventional which are 0.7 and 8.36 packets per second respectively. The result for video received in case of WFQ with committed access rate and conventional is 383.8 and 5.56 packets per seconds. Keywords Weighted Fair Queue, Committed Access Rate (CAR), IP QoS, ToS 1. INTRODUCTION Committed access rate is a method for managing unwanted traffic on the network without affecting the important traffic. CAR set high TOS for video traffic and low TOS for HTTP traffic. WFQ can prioritize the traffic and give the high bandwidth to the video traffic. CAR provides high bandwidth for video applications. CAR defines a rate-limiting feature for policing traffic, which helps managing the network's access bandwidth policy by ensuring that traffic falling within specified rate parameters is transmitted, while dropping packets that exceed the acceptable amount of traffic or transmitting them with a different priority. The input and output traffic on an interface or sub-interface may be selected based on a flexible set of criteria like all IP traffic or all traffic on an interface or based on IP precedence or MAC address or IP Access List, after which it applies the contracted rate limits, which are the parameters for a token bucket algorithm i.e. average rate, normal burst size and excess burst size. Once the packet is determined to be conforming or exceeding its limits the defined conform/ exceed action will be taken. Committed access rate can be used with the IP traffic. It doesn’t work for non-IP traffic like AppleTalk, IPX, SNA, DECNet [1]. CAR is a limiting or policing scheme which consists of certain rules based on attributes such as class of service (COS), data rate, normal burst size and excess burst size which sets a bandwidth limit for specific types of traffic on router interfaces. For example, you can create a policy that limits web traffic to 200 kilobits/sec. This puts a cap on the bandwidth available to that traffic, ensuring that the remainder of the interface’s bandwidth is available to other kinds of traffic. In this example, if web traffic does not fill 200 kilobits/sec, other kinds of traffic can use the unused bandwidth. Packets are dropped if traffic bursts exceed the limit. CAR limiting does not attempt to smooth or shape the traffic flow in the way that GTS or FRTS attempt to do. Because CAR does not buffer the traffic, there is no delay in sending it, unless the traffic flow exceeds your rate policy and it is dropped. One of the main uses for limiting policies is to ensure that traffic coming into the network is not exceeding agreed-upon rates. If the limiting policy for inbound traffic is defined, the traffic can be controlled before it gets into your network at the inbound interface [2]. Traffic policing controls the maximum rate of traffic sent or received on an interface. Based on the results of the token bucket measurement, an action can be configured to mark packets and separate packets into multiple classes or levels of service. Traffic polices provide two key benefits: Bandwidth management through rate limiting: It control the maximum rate of traffic sent or received on an interface. Traffic that falls within the rate parameters is sent, whereas traffic that exceeds the parameters is dropped, or sent with a different priority. Packet marking through IP precedence, QoS group, or DSCP value setting

QoS 적응형 플로우 기반 Active Queue Management 알고리즘 및 성능분석

방송 통신의 융합에 따라 차세대 멀티미디어 서비스인 IPTV 서비스가 각광받고 있다. IPTV 서비스는 무한한 채널수용과 미디어의 확장, 품질이 보장되는 서비스의 형태로 발전되면서 기존 네트워크의 트래픽 증가와 서비스 특성에 맞는 품질제어 기술들이 요구되고 이에 따라 플로우별 서비스 품질 제어 기술이 필요하게 되었다. 이를 위해 IETF (Internet Engineering Task Force)에서도 인터넷 상에서 IP QoS를 제공하기 위한 연구가 활발히 이루어지고 있는데 그 중 버퍼 관리 메커니즘으로 RED(Random Early Detection) 알고리즘 및 RED를 변형한 여러 가지 방법들이 제시되고 있으나 다양한 멀티미디어 서비스의 QoS 요구 사항을 충족시키는데 어려움이 있다. 이에 따라, 본 논문에서는 다양한 QoS를 요구하는 인터넷 멀티미디어 서비스를 지원하기 위해 각 서비스가 요구하는 목표 패킷 손실률을 유지시킬 수 있는 QoS적응형 플로우 기반 AQM (Active Queue Management) 알고리즘을 제안하고 ns-2를 이용한 시뮬레이션을 통해 성능 분석을 제시하였다. Due to the convergence of broadcasting and communications, IPTV services are spotlighted as the that next-generation multimedia services. IPTV services should have functionality such as unlimited channel capacity, extension of media, QoS awareness and are required increasing traffic and quality control technology to adapt the attributes of IPTV service. Consequently, flow based quality control techniques are needed. Therefore, many studies for providing Internet QoS are performed at IETF (Internet Engineering Task Force). As the buffer management mechanism among IP QoS methods, active queue management method such as RED(Random Early Detection) and modified RED algorithms have proposed. However, these algorithms have difficulties to satisfy the requirements of various Internet user QoS. Therefore, in this paper we propose the Flow based AQM(Active Queue Management) algorithm for the multimedia services that request various QoS requirements. The proposed algorithm can converge the packet loss ratio to the target packet loss ratio of required QoS requirements. And we present a performance evaluation by the simulations using the ns-2.

A Novel Fast Multi-objective Evolutionary Algorithm for QoS Multicast Routing in MANET

Multicast routing is regarded as a critical component in networks especially the real-time applications become increasingly popular in recent years. Existing multicast routing under certain QoS Constraints tend to use conventional IP QoS architecture based on GA. In this paper, we propose a novel fast multi-objective evolutionary algorithm called QMOEA for solving multicast routing problem (MRP) in MANET. The steps are that, through the analysis of the strengths and limitations of the well-known multicast architecture, we firstly give an improved Core Based Tree model to simplify the MRP. Based on this model, we then propose the QMOEA which integrates the “Greedy”and “family competition”approaches to speed up the convergence and to maintain the diversity of population. After that, we present the theoretical validations for the proposed method to show its efficiency, and finally, the performance of MANET scaled from 20 to 200 nodes with different types of service is evaluated by OPNET, our experimental res...

Design of the Cross-Layer QoS Framework for the IEEE 802.16 PMP Networks

As one of the promising techniques in Broadband Wireless Access (BWA), IEEE 802.16 also namely WiMax provides wide-area, high-speed, and non-line-of-sight wireless transmission to support multimedia services. Four service types are defined in the specification of IEEE 802.16 for QoS support. In order to achieve end-to-end multimedia services, 802.16 QoS must be well integrated with IP QoS. In this paper, we propose a framework of cross-layer QoS support in the IEEE 802.16 network. Two novel mechanisms are proposed in the framework for performance improvement: Fragment Control and Remapping. Fragment Control handles the data frames that belong to the same IP datagram in an atomic manner to reduce useless transmission. Remapping is concerned with the mapping rules from IP QoS to 802.16 QoS and is designed to reduce the impact of traffic burstiness on buffer management. Simulation study has shown that the proposed scheme has higher goodput and throughput, and lower delay than the contrast.

The Parlay network API specification

New business opportunities have emerged for network operators to offer a new generation of interfaces directly to solution providers that expose information and control in various intelligent networks. The paper describes the commercial rationale and operational benefits of these application level interfaces. The Parlay Group has defined application programming interfaces (APIs) to expose network capabilities including wireline, mobile, IP QoS, and messaging to external enterprises. The Parlay Group and the API specification are described, together with an illustration of how the API could be used to create an enterprise workflow solution that integrates capabilities in different networks.

DSL 광대역 접속망에서 DiffServ QoS 지원 방안

인터넷상에서 IP QoS를 제공하기 위한 IntServ와 DiffServ 구조 중 현재 DiffServ가 기술적, 경제적으로 현실적인 방안으로 받아들여지고 있다. 본 논문에서는 DSL 광대역 접속망에 적용될 수 있는 몇 가지 DiffServ QoS 지원 방안을 제시하고, 각 방안의 장단점 분석을 통해 기존 최선형 DSL망으로부터 DiffServ QoS지원 DSL망으로의 바람직한 이행 경로를 제시하고자 한다. DSL망은 전 세계적으로 최근에 매우 광범위하게 구축되어 있기 때문에 DiffServ QoS 지원 방안 설계 시에 다양한 QoS 서비스의 효율적인 제공뿐만 아니라, QoS 지원을 위한 신규 투자비용, 기존의 QoS 미지원 시스템과의 호환성, 기존 과금 체계와의 호환성 등이 중요하게 고려되어야 한다. 본 논문은 DSL망을 위한 DiffServ QoS 지원 방안들을 단기적으로 적용할 수 있는 정적 DiffServ 방안과 장기적으로 적용할 수 있는 동적 DiffServ 방안으로 구분하여 제시한다. 정적 DiffServ 지원 방안은 가입자 단위의 DiffServ QoS를 제공하는 평면적 DiffServ와 가입자 단위의 DiffServ QoS와 서비스 단위의 DiffServ QoS를 동시에 제공하는 구조적 DiffServ 방안을 포함하고, 동적 DiffServ 방안은 P2P(Peer to Peer) 멀티미디어 응용에 적용될 수 있는 직접 DiffServ와 ASP(Application Service Provider) 응용에 적용될 수 있는 간접 DiffServ를 포함한다. From both techlical and economic viewpoints, DiffServ IP QoS architecture is accepted as a more practical solution because of the complexity Problem of the other IntServ architecture. In this paper, we propose several models to support DiffServ QoS in DSL broadband access networks and discuss about migration path from current best-effort DSL networks to DiffServ-enabled ones. Since DSL networks are recently and widely deployed in the world amount ot new investment, compatibility with existing QoS-unaware DSL systems, and compatibility with existing charging systems as well as effective support of various QoS services must be carefully considered when we design DiffServ QoS support models in DSL networks. The DiffServ models proposed in this paper are divided into static DiffServ models and dynamic DiffServ models which are near-term solutions and long-term solutions repecitively. The static DiffServ models include Flat DiffServ which suworts per-subscriber DiffServ QoS and Structured DiffServ which supports per-subscriber and per-service DiffServ QoS. And the dynamic DiffServ models include Direct DiffServ for P2P(Peer to Peer) applications and Indirect DiffServ for ASP(Application Service Provider) applications.

Can diffserv guarantee IP QoS under failures?

As ISPs and telcos converge toward all-IP network infrastructures, the problem of service reliability becomes more acute. In this article, we investigate to what extent DiffServ can provide service protection against optical failures in IP over optical (WDM) networks. For this, we propose two mechanisms: a DiffServ/WDM method and a WDM differentiated protection technique that we call DiffProtect. Results show that the priority traffic is equally well protected by both techniques. However, for medium-priority traffic, there is an improvement in delay and jitter under failure when DiffServ is used. Thus, the proposed DiffServ implementation can be used as an affordable and effective fault management technique to protect high-priority traffic with little delay

Measuring the Perceived Importance of Speech Segments for Transmission over IP Networks

SUMMARY This paper presents a way of using a linear regression model to produce a single-valued criterion that indicates the perceived importance of each block in a stream of speech blocks. This method is superior to the conventional approach, voice activity detection (VAD), in that it provides a dynamically changing priority value for speech segments with finer granularity. The approach can be used in conjunction with scalable speech coding techniques in the context of IP QoS services to achieve a flexible form of quality control for speech transmission. A simple linear regression model is used to estimate a mean opinion score (MOS) of the various cases of missing speech segments. The estimated MOS is a continuous value that can be mapped to priority levels with arbitrary granularity. Through subjective evaluation, we show the validity of the calculated priority values.

Dynamic capacity allocation for quality-of-service support in ip-based satellite networks

In broadband satellite access networks, the efficient management of the return channel transmission capacity is key in reducing the service cost while satisfying the QoS requirements of IP-based multimedia applications. In this article a dynamic capacity allocation scheme based on combined free/demand assignment multiple access is proposed, allowing the return channel capacity to be efficiently shared among many user terminals. Simulation results indicate that the proposed scheme provides adequate DiffServ IP QoS support while maintaining high satellite bandwidth utility and reduced DCA signaling overhead.

Extensions for Internet QoS paradigms to mobile IP: a survey

Mobile IP has been chosen as the core mobility management mechanism for wireless LANs, 3G cellular networks, and, most recently, aeronautical networks. It is viewed as a key element in providing a universal roaming solution across different wireless access technologies. However, mobile IP in its basic form inherits the IP incapability to provide QoS guarantees. This results in mobile IP's lack of support for seamless intradomain mobility. This article surveys extensions that have been proposed to enhance the QoS functionality of mobile IP. It gives a brief overview of mobile IP and Internet QoS paradigms, and describes their general shortcomings with regard to QoS and mobility, respectively. It then discusses the extensions that have been proposed in the literature and provides a qualitative comparison.

Commercial models for IP quality of service interconnect

Interconnection of IP QoS capabilities between networks releases considerable value. In this paper we show where this value will be realised. We give technical and economic arguments for why QoS will be provided in core and backbone networks as a bulk QoS facility incapable of distinguishing or charging differentially between sessions, while between edge networks a vibrant mix of retail QoS solutions will be possible, including Internet-wide per-flow guarantees.We outline cutting edge research on how to co-ordinate QoS between networks, using a session-based overlay between the edges that will extract most surplus value, underpinned by a bulk QoS layer co-ordinating the whole. We survey today’s interconnect tariffs and the current disconnected state of IP QoS. Then we describe a commercial ‘model of models’ that allows incremental evolution towards an interconnected future.The paper covers intertwined engineering and economic/commercial issues in some depth, but considerable effort has been made to allow both communities to understand the whole paper.

IP connectivity for gateway GPRS support node

In the Universal Mobile Telecommunications System, the gateway GPRS support node (GGSN) provides IP connection between the mobile telecommunications network and external packet data networks (e.g., the Internet). Specifically, the GGSN exercises session management to transfer user packets between mobile stations and external data networks. In this article we focus on the GGSN functions for IP connection including access point name processing, IP address allocation, tunneling technologies, and QoS management. Based on our experience as a mobile operator, we give several examples to show how these functions can actually be implemented in a commercial mobile network.

On the building blocks of quality of service in heterogeneous IP networks

After more than a decade of active research on Quality of Service in IP networks and the Internet, the majority of IP traffic relies on the conventional best-effort IP service model. Nevertheless, some QoS mechanisms are deployed in current networking infrastructures, while emerging applications pose QoS challenges. This survey brings into the foreground a broad range of research results on Quality of Service in IP-based networks. First, a justification of the need for QoS is provided, along with challenges stemming from the convergence of IP and wireless networks and the proliferation of QoS-demanding IP applications (such as VoIP). It is also emphasized that a global uniform end-to-end IP QoS solution is not realistic. Based on this remark, packet-level QoS mechanisms are classified as certain building blocks, each one fulfilling different objectives in certain parts of a heterogeneous IP network. This taxonomy, being in line with the ITU-T initiative toward a QoS architectural framework for IP networks, gives rise to a thorough presentation of QoS “building blocks,” as well as their associated mechanisms. This presentation is followed by an illustration of how the various building blocks are combined in the scope of modern IP networks. However, offering QoS in a large scale IP-based network demands that additional (i.e. non-packet-level) QoS mechanisms are deployed in some parts. Therefore, we also present prominent technologies and mechanisms devised to augment the QoS capabilities of access, wireless, and optical networks. We illustrate how these mechanisms boost end-to-end QoS solutions and reveal interworking issues with packet-level mechanisms.