Chapter 42 Configuring PFC QoS

Common QoS Scenarios

This is the QoS classification scheme for the traffic arriving on an access layer port:

•Voice traffic: DSCP 46 (highest priority)

•Voice signaling traffic: DSCP 24 (medium priority)

•PC SAP traffic: DSCP 25 (medium priority)

•All other PC traffic: DSCP 0 (best effort)

This classification strategy provides a way to support three different classes of service on the network:

•High priority for voice traffic

•Medium priority for voice signaling and important application traffic

•Low priority for the remaining traffic

You can alter this model to fit other network environments.

PFC QoS can trust received priorities or assign new priorities by applying a QoS policy to the traffic. You configure a QoS policy using the Modular QoS CLI (MQC). In the access switches, the traffic is identified using ACLs, which differentiate the various traffic types entering the port. Once identified, a QoS policy marks the traffic with the appropriate DSCP value. These assigned DSCP values will be trusted when the traffic enters the distribution and core routers.

The port on the access router where the phone and PC are attached has been configured for a voice VLAN (VLAN 110), which is used to separate the phone traffic (subnet 10.1.110.0/24) from the PC traffic (10.1.10.0/24). The voice VLAN subnet uniquely identifies the voice traffic. The UDP and TCP port numbers identify the different applications.

This is the access port access control list (ACL) configuration:

Identify the Voice Traffic from an IP Phone (VVLAN)

ip access-list extended CLASSIFY-VOICE

permit udp 10.1.110.0 0.0.0.255 any range 16384 32767

Identify the Voice Signaling Traffic from an IP Phone (VVLAN)

ip access-list extended CLASSIFY-VOICE-SIGNAL

permit udp 10.1.110.0 0.0.0.255 any range 2000 2002

Identify the SAP Traffic from the PC (DVLAN)

ip access-list extended CLASSIFY-PC-SAP

permit tcp 10.1.10.0 0.0.0.255 any range 3200 3203 permit tcp 10.1.10.0 0.0.0.255 any eq 3600 any

ip access-list extended CLASSIFY-OTHER permit ip any any

The next step in configuring the QoS policy is to define the class maps. These class maps associate the identifying ACLs with the QoS actions that you want to perform (marking, in this case). This is the syntax for the class maps:

class-map match-all CLASSIFY-VOICE

match access-group name CLASSIFY-VOICE class-map match-all CLASSIFY-VOICE-SIGNAL

match access-group name CLASSIFY-VOICE-SIGNAL class-map match-all CLASSIFY-PC-SAP

match access-group name CLASSIFY-PC-SAP class-map match-all CLASSIFY-OTHER

match access-group name CLASSIFY-OTHER

 

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OL-4266-08

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Cisco Systems OL-4266-08 Identify the Voice Traffic from an IP Phone Vvlan, Identify the SAP Traffic from the PC Dvlan
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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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