Chapter 42 Configuring PFC QoS

Understanding How PFC QoS Works

Port Trust

In PFC QoS, trust means to accept as valid and use as the basis of the initial internal DSCP value. You can configure ports as untrusted or you can configure them to trust these QoS values:

•Layer 2 CoS

–A port configured to trust CoS is called a trust CoS port.

–Traffic received through a trust CoS port or configured by a policy map to trust CoS is called trust CoS traffic.

Note Not all traffic carries a CoS value. Only ISL, 802.1Q, and 802.1P traffic carries a CoS value. PFC QoS applies the port CoS value to any traffic that does not carry a CoS value. On untrusted ports, PFC QoS applies the port CoS value to all traffic, overwriting any received CoS value.

•IP precedence

–A port configured to trust IP precedence is called a trust IP precedence port.

–Traffic received through a trust IP precedence port or configured by a policy map to trust IP precedence is called trust IP precedence traffic.

•DSCP

–A port configured to trust DSCP is called a trust DSCP port.

–Traffic received through a trust DSCP port or configured by a policy map to trust DSCP is called trust DSCP traffic.

Traffic received through an untrusted port is called untrusted traffic.

Ingress Congestion Avoidance

PFC QoS implements congestion avoidance on trust CoS ports. On a trust CoS port, QoS classifies the traffic on the basis of its Layer 2 CoS value and assigns it to an ingress queue to provide congestion avoidance. In Release 12.2(18)SXF5 and later releases, you can configure WS-X6708-10GE trust DSCP ports to use received DSCP values for congestion avoidance. See the “Ingress Classification and Marking at Trust CoS LAN Ports” section on page 42-17for more information about ingress congestion avoidance.

PFC and DFC QoS Features

These sections describe PFCs and DFCs as they relate to QoS:

•Supported Policy Feature Cards, page 42-9

•Supported Distributed Forwarding Cards, page 42-9

•PFC and DFC QoS Feature List and Flowchart, page 42-9

•Internal DSCP Values, page 42-11

Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX

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OL-4266-08

 

 

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Cisco Systems OL-4266-08 manual PFC and DFC QoS Features, Port Trust, Ingress Congestion Avoidance, 42-8
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OL-4266-08 specifications

Cisco Systems OL-4266-08 is a robust and versatile certification that focuses on the essentials of implementing and troubleshooting Cisco collaborations solutions. As enterprises increasingly rely on unified communications, having professionals who are knowledgeable in the latest Cisco technologies becomes a necessity. This certification is part of the Cisco Certified Network Associate (CCNA) program, which serves as a foundational stepping stone for individuals aspiring to build a career in networking and collaboration technologies.

One of the main features of OL-4266-08 is its emphasis on collaboration foundations, which includes an understanding of voice, video, messaging, and conferencing technologies. Professionals who obtain this certification demonstrate proficiency in deploying, configuring, and troubleshooting Cisco collaboration solutions like Cisco Unified Communications Manager and Cisco Webex. This knowledge is critical as businesses seek to enhance communication and productivity through integrated systems.

Technologically, OL-4266-08 covers a wide array of essential concepts, including IP telephony, voicemail, and collaborative tools. Candidates learn about the architecture of unified collaboration systems, involving integration with routing and switching networks. Additionally, it delves into security protocols to ensure secure transmissions of voice and video data, thereby protecting sensitive corporate communication.

In terms of characteristics, OL-4266-08 is designed to be both comprehensive and practical. The certification emphasizes hands-on experience, which is essential for understanding real-world applications of Cisco technologies. The coursework provides extensive exposure to simulations and labs that mimic actual network environments. This hands-on approach enables candidates to troubleshoot issues effectively using Cisco's troubleshooting tools and methodologies.

Moreover, the certification aligns with industry standards, ensuring that individuals gain relevant and in-demand skills. Given the evolving landscape of network technologies, OL-4266-08 prepares individuals for future growth and specialization in various areas, including cloud collaboration and Internet of Things (IoT) communications.

In conclusion, Cisco Systems OL-4266-08 equips networking professionals with the necessary skills to implement and support Cisco collaboration solutions. The focus on hands-on experience, along with in-depth coverage of technology and security protocols, makes it a valuable certification in the fast-paced world of network communications. With the rise of remote work and digital collaboration, this certification is pivotal for anyone looking to enhance their career in networking and technology.
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