Quality of Service Networking Doc. Wiki. From Doc. Wiki. Quality of Service Qo. S refers to the capability of a network to provide better service to selected network traffic over various technologies, including Frame Relay, Asynchronous Transfer Mode ATM, Ethernet and 8. SONET, and IP routed networks that may use any or all of these underlying technologies. The primary goal of Qo. S is to provide priority including dedicated bandwidth, controlled jitter and latency required by some real time and interactive traffic, and improved loss characteristics. Also important is making sure that providing priority for one or more flows does not make other flows fail. Qo. S technologies provide the elemental building blocks that will be used for future business applications in campus, WAN, and service provider networks. This article outlines the features and benefits of the Qo. S provided by the Cisco IOS Qo. S. The Cisco IOS Qo. S software enables complex networks to control and predictably service a variety of networked applications and traffic types. Almost any network can take advantage of Qo. S for optimum efficiency, whether it is a small corporate network, an Internet service provider, or an enterprise network. The Cisco IOS Qo. S software provides these benefits. Control over resources You have control over which resources bandwidth, equipment, wide area facilities, and so on are being used. For example, you can limit the bandwidth consumed over a backbone link by FTP transfers or give priority to an important database access. More efficient use of network resources Using Ciscos network analysis management and accounting tools, you will know what your network is being used for and that you are servicing the most important traffic to your business. Tailored services The control and visibility provided by Qo. S enables Internet service providers to offer carefully tailored grades of service differentiation to their customers. Coexistence of mission critical applications Ciscos Qo. S technologies make certain that your WAN is used efficiently by mission critical applications that are most important to your business, that bandwidth and minimum delays required by time sensitive multimedia and voice applications are available, and that other applications using the link get their fair service without interfering with mission critical traffic. Foundation for a fully integrated network in the future Implementing Cisco Qo. S technologies in your network now is a good first step toward the fully integrated multimedia network needed in the near future. Contents. 1Qo. S Concepts. Basic Qo. S Architecture. C C Programmiersprache IT C Country X. Adressierung, Land IT C Kohlenstoff Chemisches Element C Kollektor Transistor Elektronik C privater Konsum. The corner of a tablet screen displaying a call center floorplan diagram in Visio image. The Cisco IOS QoS software enables complex networks to control and predictably service a variety of networked applications and traffic types. Almost any network can. Qo. S Identification and Marking. Qo. S Within a Single Network Element. Qo. S Management. End to End Qo. S Levels. Classification Identifying Flows. NetworkViewer.png' alt='Automatic Network Topology Diagram Software' title='Automatic Network Topology Diagram Software' />IP Precedence Differentiated Qo. S9. Congestion Management Tools. Queue Management Congestion Avoidance Tools1. Traffic Shaping and Policing Tools. Link Efficiency Mechanisms. Qo. S Management. Qo. S on Ethernet. Multiprotocol Label Switching Allowing Flexible Traffic Engineering. Qo. S Policy Control. SNA To. S1. 8Qo. S for Packetized Voice. Qo. S for Streaming Video. Summary. 21. Review Questions. For More Information Qo. S Concepts Fundamentally, Qo. S enables you to provide better service to certain flows. This is done by either raising the priority of a flow or limiting the priority of another flow. When using congestion management tools, you try to raise the priority of a flow by queuing and servicing queues in different ways. The queue management tool used for congestion avoidance raises priority by dropping lower priority flows before higher priority flows. Policing and shaping provide priority to a flow by limiting the throughput of other flows. Link efficiency tools limit large flows to show a preference for small flows. Cisco IOS Qo. S is a tool box, and many tools can accomplish the same result. A simple analogy comes from the need to tighten a bolt You can tighten a bolt with pliers or with a wrench. Both are equally effective, but these are different tools. This is the same with Qo. S tools. You will find that results can be accomplished using different Qo. S tools. Which one to use depends on the traffic. You wouldnt pick a tool without knowing what you were trying to do, would you If the job is to drive a nail, you do not bring a screwdriver. Qo. S tools can help alleviate most congestion problems. However, many times there is just too much traffic for the bandwidth supplied. In such cases, Qo. S is merely a bandage. A simple analogy comes from pouring syrup into a bottle. Syrup can be poured from one container into another container at or below the size of the spout. If the amount poured is greater than the size of the spout, syrup is wasted. However, you can use a funnel to catch syrup pouring at a rate greater than the size of the spout. This allows you to pour more than what the spout can take, while still not wasting the syrup. However, consistent overpouring will eventually fill and overflow the funnel. Basic Qo. S Architecture The basic architecture introduces the three fundamental pieces for Qo. S implementation see Figure A Basic Qo. S Implementation Has Three Main Components. Qo. S identification and marking techniques for coordinating Qo. S from end to end between network elements. Qo. S within a single network element for example, queuing, scheduling, and traffic shaping tools. Qo. S policy, management, and accounting functions to control and administer end to end traffic across a network. Figure A Basic Qo. S Implementation Has Three Main Components Qo. S Identification and Marking Identification and marking is accomplished through classification and reservation. Classification To provide preferential service to a type of traffic, it must first be identified. Second, the packet may or may not be marked. These two tasks make up classification. When the packet is identified but not marked, classification is said to be on a per hop basis. This is when the classification pertains only to the device that it is on, not passed to the next router. This happens with priority queuing PQ and custom queuing CQ. When packets are marked for network wide use, IP precedence bits can be set see the section IP Precedence Signaling Differentiated Qo. S. Common methods of identifying flows include access control lists ACLs, policy based routing, committed access rate CAR, and network based application recognition NBAR. Qo. S Within a Single Network Element Congestion management, queue management, link efficiency, and shapingpolicing tools provide Qo. S within a single network element. Congestion Management Because of the bursty nature of voicevideodata traffic, sometimes the amount of traffic exceeds the speed of a link. At this point, what will the router do Will it buffer traffic in a single queue and let the first packet in be the first packet outOr, will it put packets into different queues and service certain queues more often Congestion management tools address these questions. Tools include priority queuing PQ, custom queuing CQ, weighted fair queuing WFQ, and class based weighted fair queuing CBWFQ. Queue Management Because queues are not of infinite size, they can fill and overflow. When a queue is full, any additional packets cannot get into the queue and will be dropped. This is a tail drop. Cisco Find. IT Network Management Cisco. Manage a Network, Not a Collection of Devices. Maintaining a business network is difficult without the right tools. Cisco Find. IT Network Management is purpose built for managing networks of Cisco 1. Series devices. It lets you proactively manage the network instead of just reacting to events. Find. IT Network Management is the perfect addition to your businesss network. Features and Capabilities. Accounting Software For Option Trading. Find. IT Network Management supports two deployment models full time network management with the Find. IT Network Manager and Probe, and discovering and managing the network on the go with the Find. IT Network Discovery Utility. Easy Network Management. The Find. IT Network Manager and Probe are designed to manage Cisco 1. Series switches, routers, and wireless access points. You can configure system information, wireless networks, virtual LANs, and Ethernet switching in a single interface. And you can monitor network performance with a customizable dashboard. Automatic network discovery comes with a topology diagram and an inventory report. In addition, you get Automatic firmware updates for network devices. Detailed lifecycle reports showing maintenance status and end of life bulletins. Integration with the Cisco Active Advisor. Remote access to sites without requiring a VPNOne click collection of diagnostic data for technical support. Handy Plug In. The Find. IT Network Discovery Utility can be used by network administrators on the go. It integrates with your web browser and allows you to easily discover Cisco 1. Series products, display detailed information about devices, and click to download firmware updates. The Find. IT Network Discovery Utility runs on Apple Safari, Google Chrome, Microsoft Internet Explorer, and Mozilla Firefox browsers on Microsoft Windows and Apple OS X. It provides Automatic discovery and information display for Cisco 1. Series products. Automatic discovery and one click downloads for firmware updates. Support and maintenance information for discovered devices. Integration with the Cisco Active Advisor. Direct access to the Small Business Support Center.