qos quality of service

... 2-1: QoS Mechanisms Review customer QoS requirements Completely read the customer requirements provided Identify QoS service class requirements With the aid of your partner, identify the service ... Systems, Inc All rights reserved QoS v2.2—6 Case Study Results: JC Whitney Service Classes © 2006 Cisco Systems, Inc All rights reserved QoS v2.2—18 Case Study Results: QoS Service Class Requirements ... rights reserved QoS v2.2—21 Visual Objective for Case Study 6-1: WRED Traffic Profiles Review customer QoS requirements Completely read the customer requirements provided Identify QoS service class...

Ngày tải lên: 04/07/2014, 01:20

... Fast Retransmit o Probability p of choosing a given flow is proportional to the rate of the flow l more packets of that flow, higher probability of choosing one of its packets Queue Management ... Principles for QOS Guarantees (more) o Alternative to Marking and Policing: allocate a set portion of bandwidth to each application flow; can lead to inefficient use of bandwidth if one of the flows ... Management Improving QOS in IP Networks o IETF groups are working on proposals to provide better QOS control in IP networks, i.e., going beyond best effort to provide some assurance for QOS o Work in...

Ngày tải lên: 06/04/2013, 11:05

... is not covered in this book.) Some of the problems QoS cannot solve are propagation delay (no solution to the speed -of- light problem exists as of the printing of this book), codec delay, sampling ... classes of service You can base policies on IP addresses, port numbers, protocols, or the size of packets You can use one of these descriptors to create a simple policy, or you can use all of them ... classes of service WRED also is RSVP aware, and it can provide an IS controlled-load QoS service To fully comprehend how WRED works, you must understand TCP packet loss behavior TCP A stream of data...

Ngày tải lên: 30/09/2013, 05:20

... throughput reflects the Quality of Service from the viewpoints of the application and user The focus of the thesis is on the influence of the network on the applicationperceived Quality of Service and thus ... (ITU-T) defines QoS as “the collective effect of service performance, which determines the degree of satisfaction of a user of a service. ” Others, e.g [6], define QoS as “a collection of technologies ... UE Uu BS Iub RNC Iu CN End-to-End Service UMTS Bearer Service Radio Access Bearer Service Radio Bearer Service UTRA Service Iu Bearer Service Physical Bearer Service Figure 2.6: UTRAN architecture...

Ngày tải lên: 18/10/2013, 12:15

... Improve Quality of Service Improving Grade of Service (GOS) While Reducing RF Channels Wireless service providers are adopting new deployment strategies to reduce network costs and improve quality of ... or more of the total number of RF channels required on a multiple link transport system for a specified amount of user grade of service The percentage reduction depended on the number of radiating ... “grade of service (GOS), which is the acceptable amount of network blocking of incoming call attempts Typical wireless network designs in the United States provision channels to provide voice services...

Ngày tải lên: 10/12/2013, 19:15

... sorted into various types of service at the basic perimeter of the network and that those types of service should be implemented in the core of the network Routers in the core of the network can then ... many QoS features are based on the IP Precedence bit or DSCP settings There are methods of marking that will map Layer Class of Service (CoS) bits to Layer IP Precedence or DSCP settings A QoS- group ... 10 What Is Modular QoS CLI (MQC)? Modular QoS CLI (MQC): • Is how you configure QoS policy • Separates the definition of classes from the application of QoS mechanisms MQC is template-based: •...

Ngày tải lên: 11/12/2013, 14:15

... Objectives Upon completion of this module, you will be able to perform the following tasks: • Explain the significance of Quality of Service (QoS) • Describe new Quality of Service (QoS) features in Cisco ... problems QoS solves Keep All Graphics Inside This Box © 2000, Cisco Systems, Inc www.cisco.com Econ_0385_02_010 pt p The purpose of this module is to quickly survey the new Quality of Service (QoS) ... database access • Tailored services—If you are an Internet Service Provider (ISP), the control and visibility provided by QoS enables you to offer carefully tailored grades of service differentiation...

Ngày tải lên: 11/12/2013, 14:15

... pt p The objective of this module is to define the quality of service (QoS) tools which must be implemented to provide a voice-enabled transport service for IP telephony A QoS- enabled transport ... 802.1p field (referred to as class of service or CoS), which is part of the 802.1Q tag • At Layer using the bits of DSCP field in the type of service (ToS) byte of the IP header Classification is ... 3, however many QoS features are based on the IP Precedence bit or Differentiated Services Code Point (DSCP) settings There are methods of marking that will map Layer Class of Service (CoS) bits...

Ngày tải lên: 11/12/2013, 14:15

... Four cases of congestion 24.22 24-5 QUALITY OF SERVICE Quality of service (QoS) is an internetworking issue that has been discussed more than defined We can informally define quality of service ... 24-1 DATA TRAFFIC The main focus of congestion control and quality of service is data traffic In congestion control we try to avoid traffic congestion In quality of service, we try to create an appropriate ... TECHNIQUES TO IMPROVE QoS In Section 24.5 we tried to define QoS in terms of its characteristics In this section, we discuss some techniques that can be used to improve the quality of service We briefly...

Ngày tải lên: 06/03/2014, 12:20

... Further reading 5.9 References Quality of service 6.1 Introduction 6.2 Routing in mobile ad hoc networks 6.3 Routing with quality of service constraints 6.4 Quality of service routing in ad hoc networks ... studies of ad hoc networks with QoS constraints continue to be an active area of research Chapter discusses the state of the art of quality of service in ad hoc networks and is a good source of more ... associated with providing quality of service (QoS) in ad hoc networks It should be pointed out that security and quality of service are two distinct attributes that are independent of each other in general...

Ngày tải lên: 25/03/2014, 12:07

... the QoS of both schemes by means of extensive system simulations in terms of data throughput as well as delay However, we also consider the fairness of both schemes as an additional important QoS ... error rate; PBOA: Progressive Backoff Algorithm; PHY: physical layer; QoS: quality of service; SINR: signal-tointerference-and-noise-ratio Author details Institute of Communication Networks, Technische ... first part of the frame is related to a contention phase and consists of several pairs of minislots Each minislot is divided into the transmission of an RTS and a CTS signal The second part of the...

Ngày tải lên: 21/06/2014, 03:20

... prepared to present state of the art on WiMAX Technology It has been constructed with the support of many researchers around the world, working on resource allocation, quality of service and WiMAX applications ... predefined Quality of Service (QoS) framework, enabling efficient and scalable networks for data, video, and voice However, the standard does not define the scheduling algorithm which guarantees the QoS ... associated with a service class The IEEE 802.16 standards define five service classes: Unsolicited Grant Service (UGS), extended real-time Polling Service (ertPS), real-time Polling Service (rtPS),...

Ngày tải lên: 21/06/2014, 05:20

... downlink of a cellular WiMAX network where a number of base stations need to communicate simultaneously with their respective active users Each of these users has typically a certain Quality of Service ... backlog of data to be transmitted 106 Quality of Service and Resource Allocation in WiMAX Will-be-set-by-IN-TECH The rest of the chapter is organized as follows In Section 2, the different kinds of ... this type of traffic it will be sent in no time For accurate performance evaluation, we adopt the WiMAX physical layer standard OFDM_BPSK_1_2 in our simulations [24] 100 Quality of Service and...

Ngày tải lên: 21/06/2014, 05:20

... analysis of the network in the limit of large number of users The aim of this approach is to obtain optimal values of the resuse factor that no longer depend on the particular configuration of the ... current level of multicell interference The result of each iteration is then used to update the value of multicell interference for the next iteration of the algorithm The convergence of this iterative ... positions of users, their single QoS requirements, etc, but rather on an asymptotic, or “average”, state of the network e.g., density of users’ geographical distribution, average rate requirement of...

Ngày tải lên: 21/06/2014, 05:20

... defines a concept of a service flow A service flow is a unidirectional flow of packets with a particular set of QoS parameters and is identified by a service flow identifier (SFID) The QoS parameters ... the format of the OFDMA slot is data subcarriers of OFDM symbols The total number of OFDMA slots in a mobile WiMAX frame corresponds to S × Ts where S = Ld and Ts is the number of OFDM symbol ... satisfy QoS constraints of each connection The mapping mechanism is left to the choice of the provider State of the art 3.1 Bandwidth sharing strategies: background To maintain a quality of service...

Ngày tải lên: 21/06/2014, 05:20

... in OFDMA systems, Proceedings of IEEE Signal Processing Systems, 2004 SIPS 2004, pp 1-6, october 2004 Part Quality of Service Models and Evaluation A Unified Performance Model for Best-Effort Services ... PMP mode In WiMAX networks, quality of service (QoS) is provided through five different services classes in the MAC layer (Andrews et al., 2007): Unsolicited grant service (UGS) is designed for ... traffic load of an SS, ρ In the following, we will develop the outer set of fixed point equations for ρ 3.2 Mean service time of an REQ This subsection presents the details of Block B of Fig 2, which...

Ngày tải lên: 21/06/2014, 05:20

... the growing demands of fixed and mobile users, while increasing the profits of the content providers With regard to Quality of Service (QoS) control, the WiMAX system provides service differentiation ... a link with the service flow characteristics of this connection Fig Overall Architecture of WiMAX QoS 200 Quality of Service and Resource Allocation in WiMAX After the process of classification ... the quality level of multimedia streaming from the 194 Quality of Service and Resource Allocation in WiMAX perspective of the network , but not reflect the user’s experience As a result, these QoS...

Ngày tải lên: 21/06/2014, 05:20

... Perceived QoS (or Quality of Experience – QoE) is often considered as the “ultimate measure” of system performance According to ITU-T one can describe QoS as the ‘degree of objective service performance’ ... example of the process of estimating resources for four frames 226 Quality of Service and Resource Allocation in WiMAX Value of guard channel (threshold) is adjusted based on the value of the ... results of assessing quality of VoIP (Voice Over IP) conversations CTC and nbLDPC codes are compared in terms of system capacity and resulting quality of experience (QoE) performance of VoIP...

Ngày tải lên: 21/06/2014, 05:20

... alarm, and can be re-produced with upper quality at the expense of better service treatment of HD video data With introduction of categorized treatment of quality- selected video flows the surveillance ... agreed QoS characteristics The novel 250 Quality of Service and Resource Allocation in WiMAX admission and congestion control scheme, introduced in the paper, performs regular analysis of traffic QoS ... Unsolicited Grant Service (UGS) type of QoS to the biosignal traffic and voice conversation; Real-time Priority Service (rtPS) service for the video transmission; Non-real-time Priority Service (nrtPS)...

Ngày tải lên: 21/06/2014, 05:20

... support joint operation with it 274 Quality of Service and Resource Allocation in WiMAX One of the drivers of WiMAX’s development is its suitability (because of centralized scheduling using TDD) ... 276 Quality of Service and Resource Allocation in WiMAX WiMAX and IP handoff management (Chen & Hsieh, 2007) and in that way reduce the number of control messages For further general examples of ... inter-packet gap of 0.03 s was also downloaded to a third MS WiMAX has a set of quality- of- service queues at a BS While the CBR and FTP traffic occupy the non-rtPS (non-real-time polling service) queue,...

Ngày tải lên: 21/06/2014, 05:20