Chapter 42 Configuring PFC QoS

Understanding How PFC QoS Works

These sections describe classification and marking at trusted ingress ports:

•Ingress Classification and Marking at Trust CoS LAN Ports, page 42-17

•Ingress Classification and Marking at Trust IP Precedence Ports, page 42-17

•Ingress Classification and Marking at Trust DSCP Ports, page 42-17

Ingress Classification and Marking at Trust CoS LAN Ports

You should configure LAN ports to trust CoS only if they receive traffic that carries valid Layer 2 CoS.

When an ISL frame enters the router through a trusted ingress LAN port, PFC QoS accepts the three least significant bits in the User field as a CoS value. When an 802.1Q frame enters the router through a trusted ingress LAN port, PFC QoS accepts the User Priority bits as a CoS value. PFC QoS Layer 2 remarking marks all traffic received in untagged frames with the ingress port CoS value.

On ports configured to trust CoS, PFC QoS does the following:

•PFC QoS maps the received CoS value in tagged trust CoS traffic to the initial internal DSCP value.

•PFC QoS maps the ingress port CoS value applied to untagged trusted traffic to the initial internal DSCP value.

•PFC QoS enables the CoS-based ingress queues and thresholds to provide congestion avoidance. See the “Understanding Port-Based Queue Types” section on page 42-22for more information about ingress queues and thresholds.

Ingress Classification and Marking at Trust IP Precedence Ports

You should configure ports to trust IP precedence only if they receive traffic that carries valid Layer 3 IP precedence. For traffic from trust IP precedence ports, PFC QoS maps the received IP precedence value to the initial internal DSCP value. Because the ingress port queues and thresholds use Layer 2 CoS, PFC QoS does not implement ingress port congestion avoidance on ports configured to trust IP precedence. PFC does not mark any traffic on ingress ports configured to trust IP precedence.

Ingress Classification and Marking at Trust DSCP Ports

You should configure ports to trust DSCP only if they receive traffic that carries valid Layer 3 DSCP.

In Release 12.2(18)SXF5 and later releases, you can enable DSCP-based ingress queues and thresholds on WS-X6708-10GE ports to provide congestion avoidance (see the “Configuring DSCP-Based Queue Mapping” section on page 42-98).

In releases earlier than Release 12.2(18)SXF5, the ingress port queues and thresholds use only Layer 2 CoS, and PFC QoS does not implement ingress port congestion avoidance on ports configured to trust DSCP.

For traffic from trust DSCP ports, PFC QoS uses the received DSCP value as the initial internal DSCP value. PFC QoS does not mark any traffic on ingress ports configured to trust received DSCP.

Classification and Marking at Ingress OSM Ports

PFC QoS associates CoS zero with all traffic received through ingress OSM ports. You can configure ingress OSM port trust states that can be used by the PFC to set IP precedence or DSCP values and the CoS value. You can configure the trust state of each ingress OSM port as follows:

•Untrusted (default)

•Trust IP precedence

•Trust DSCP

 

 

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

 

 

 

 

 

 

OL-4266-08

 

 

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Cisco Systems OL-4266-08 manual Classification and Marking at Ingress OSM Ports, 42-17
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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.

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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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