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Written by Administrator
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Saturday, 20 June 2009 11:26 |
Major QoS Features in Cisco IOS
Cisco supports three end-to-end QoS models namely, Best-Effort Service, Integrated Services and Differentiated Services. Cisco provides many features to implement these QoS models.
ClassificationClassifying network traffic allows you to organize traffic into traffic classes or categories on the basis of whether the traffic matches a given specific criteria. Network-Based Application Recognition (NBAR) is one of the classification feature.
Congestion ManagementNetwork elements handle an overflow of arriving traffic by using a queuing algorithm to sort the traffic and then determine some method of prioritizing it onto an output link. he Cisco IOS software supports following queuing features: - FIFO queuing
- Priority queuing (PQ)
- Frame Relay permanent virtual circuit (PVC) interface priority queuing (FR PIPQ)
- Custom queuing (CQ)
- Weighted fair queuing (WFQ) and distributed WFQ (DWFQ)
- Class-based WFQ (CBWFQ) and Distributed CBWFQ (DCBWFQ)
- IP RTP Priority
- Frame Relay IP RTP Priority
- Low Latency Queuing (LLQ)
- Distributed LLQ (DLLQ)
- LLQ for Frame Relay
Congestion AvoidanceWRED and DWRED are the Cisco IOS QoS congestion avoidance features.
Policing Cisco IOS QoS includes traffic policing capabilities implemented through the rate-limiting aspects of CAR and the Traffic Policing feature.
ShapingCisco IOS QoS includes Generic Traffic Shaping (GTS), Class-Based Shaping, and Frame Relay Traffic Shaping (FRTS). These features allow you to regulate packet flow on your network.
SignalingCisco IOS QoS signaling takes advantage of IP. Either in-band (IP Precedence, 802.1p) or out-of-band (RSVP) signaling is used to indicate that a particular QoS service is desired for a particular traffic classification.
Link Efficiency MechanismsCisco IOS software offers a number of link-layer efficiency mechanisms or features designed to reduce latency and jitter for network traffic, including Multilink PPP (MLPPP), Frame Relay Fragmentation and Header Compression. These mechanisms work with queuing and fragmentation to improve the efficiency and predictability of the application service levels.
Modular QoS Command-Line InterfaceThe Modular Quality of Service Command-Line Interface (MQC) is a CLI structure that allows you to define a traffic class, create a traffic policy (policy map), and attach the traffic policy to an interface.
Security Device ManagerThe Cisco Router and Security Device Manager (SDM) provides an intuitive, graphical user interface for configuring and monitoring advanced IP-based QoS functionality within Cisco routers.
AutoQoSThe AutoQoS feature allows you to automate the delivery of QoS on your network and provides a means for simplifying the implementation and provisioning of QoS. |
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Last Updated on Friday, 28 August 2009 04:55 |
