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Example 4-17. Best Practice Output Scheduling Configuration for IP Telephony Networks

Dans le document classification and marking (Page 154-157)

End-to-end QoS deployment techniques for Cisco Catalyst series switches

Examine various QoS components, including congestion management, congestion

avoidance, shaping, policing/admission control, signaling, link efficiency mechanisms, and classification and marking

Map specified class of service (CoS) values to various queues and maintain CoS values through the use of 802.1q tagging on the Cisco Catalyst 2900XL, 3500XL and Catalyst 4000 and 2948G/2980G CatOS Family of Switches

Learn about classification and rewrite capabilities and queue scheduling on the Cisco Catalyst 5000

Implement ACLs, ACPs, ACEs, and low-latency queuing on the Cisco Catalyst 2950 and 3550 Family of Switches

Understand classification, policying, and scheduling capabilities of the Catalyst 4000 and 4500 IOS Family of Switches

Configure QoS in both Hybrid and Native mode on the Catalyst 6500 Family of Switches Utilize Layer 3 QoS to classify varying levels of service with the Catalyst 6500 MSFC and Flexwan

Understand how to apply QoS in campus network designs by examining end-to-end case studies

Quality of service (QoS) is the set of techniques designed to manage network resources. QoS refers to the capability of a network to provide better service to selected network traffic over various LAN and WAN technologies. The primary goal of QoS is to provide flow priority, including dedicated bandwidth, controlled jitter and latency (required by some interactive and delay-sensitive traffic), and improved loss characteristics.

While QoS has become an essential technology for those organizations rolling out a new

WRED thresholds for queue 1 set to 20 and 30 and 40 and 95 on all WRED-capable 1q4t ports.

To view the number of packets dropped per threshold number, use the following command:

show qos statistics mod_num/port_num

Example 4-16 illustrates the use of the show qos statistics command.

Example 4-16. User Displaying the Number of Dropped Packet per Threshold Number

Console> (enable) show qos statistics 3/24

On Transmit: Port 3/24 has 1 Queue(s) 4 Threshold(s) Q # Threshold #:Packets dropped

--- ---1 ---1:59378 pkts, 2:---14 pkts, 3:7 pkts, 4:8 pkts

For IP telephony networks, a CoS value of 5 generally represents VoIP traffic. As a result, the desired behavior is to never drop VoIP traffic unless the output buffer queue is full. As a result, use the following best practice configuration for switch ports connected to IP telephony devices, such as Cisco IP Phones:

Example 4-17. Best Practice Output Scheduling Configuration for IP Telephony Networks

!

Table of Contents

Index

Cisco Catalyst QoS: Quality of Service in Campus Networks By Mike Flannagan CCIE® No. 7651, Richard Froom CCIE No. 5102, Kevin Turek CCIE No. 7284

Publisher: Cisco Press Pub Date: June 06, 2003

ISBN: 1-58705-120-6 Pages: 432

End-to-end QoS deployment techniques for Cisco Catalyst series switches

Examine various QoS components, including congestion management, congestion

avoidance, shaping, policing/admission control, signaling, link efficiency mechanisms, and classification and marking

Map specified class of service (CoS) values to various queues and maintain CoS values through the use of 802.1q tagging on the Cisco Catalyst 2900XL, 3500XL and Catalyst 4000 and 2948G/2980G CatOS Family of Switches

Learn about classification and rewrite capabilities and queue scheduling on the Cisco Catalyst 5000

Implement ACLs, ACPs, ACEs, and low-latency queuing on the Cisco Catalyst 2950 and 3550 Family of Switches

Understand classification, policying, and scheduling capabilities of the Catalyst 4000 and 4500 IOS Family of Switches

Configure QoS in both Hybrid and Native mode on the Catalyst 6500 Family of Switches Utilize Layer 3 QoS to classify varying levels of service with the Catalyst 6500 MSFC and Flexwan

Understand how to apply QoS in campus network designs by examining end-to-end case studies

Quality of service (QoS) is the set of techniques designed to manage network resources. QoS refers to the capability of a network to provide better service to selected network traffic over various LAN and WAN technologies. The primary goal of QoS is to provide flow priority, including dedicated bandwidth, controlled jitter and latency (required by some interactive and delay-sensitive traffic), and improved loss characteristics.

While QoS has become an essential technology for those organizations rolling out a new Console> (enable) show config

This command shows non-default configurations only.

Use 'show config all' to show both default and non-default configurations.

(text deleted)

!

#qos

set qos enable

set qos map 1q4t 1 1 cos 2 set qos map 1q4t 1 2 cos 4

set qos wred-threshold 1q4t tx queue 1 20 30 100 100

!

(text deleted) end

Console> (enable) show qos info config 1q4t tx QoS setting in NVRAM for 1q4t transmit:

QoS is enabled

Queue and Threshold Mapping:

Queue Threshold CoS

--- --- ---1 ---1 0 ---1 2

1 2 3 4 1 3 5 1 4 6 7

Queue # Thresholds - percentage

--- ---1 20% 30% ---100% ---100%

Table of Contents

Index

Cisco Catalyst QoS: Quality of Service in Campus Networks By Mike Flannagan CCIE® No. 7651, Richard Froom CCIE No. 5102, Kevin Turek CCIE No. 7284

Publisher: Cisco Press Pub Date: June 06, 2003

ISBN: 1-58705-120-6 Pages: 432

End-to-end QoS deployment techniques for Cisco Catalyst series switches

Examine various QoS components, including congestion management, congestion

avoidance, shaping, policing/admission control, signaling, link efficiency mechanisms, and classification and marking

Map specified class of service (CoS) values to various queues and maintain CoS values through the use of 802.1q tagging on the Cisco Catalyst 2900XL, 3500XL and Catalyst 4000 and 2948G/2980G CatOS Family of Switches

Learn about classification and rewrite capabilities and queue scheduling on the Cisco Catalyst 5000

Implement ACLs, ACPs, ACEs, and low-latency queuing on the Cisco Catalyst 2950 and 3550 Family of Switches

Understand classification, policying, and scheduling capabilities of the Catalyst 4000 and 4500 IOS Family of Switches

Configure QoS in both Hybrid and Native mode on the Catalyst 6500 Family of Switches Utilize Layer 3 QoS to classify varying levels of service with the Catalyst 6500 MSFC and Flexwan

Understand how to apply QoS in campus network designs by examining end-to-end case studies

Quality of service (QoS) is the set of techniques designed to manage network resources. QoS refers to the capability of a network to provide better service to selected network traffic over various LAN and WAN technologies. The primary goal of QoS is to provide flow priority, including dedicated bandwidth, controlled jitter and latency (required by some interactive and delay-sensitive traffic), and improved loss characteristics.

While QoS has become an essential technology for those organizations rolling out a new The configuration in Example 4-17 assigns traffic with CoS values of 5 to threshold #3. In this manner, the switch drops traffic for CoS values 5, 6, and 7 only when the output buffer is full. In addition, the switch aggressively drops low-priority traffic for CoS values 0 to 4 when the queue is 20 percent to 30 percent full to avoid output buffer full conditions from ever occurring.

Table of Contents

Index

Cisco Catalyst QoS: Quality of Service in Campus Networks By Mike Flannagan CCIE® No. 7651, Richard Froom CCIE No. 5102, Kevin Turek CCIE No. 7284

Publisher: Cisco Press Pub Date: June 06, 2003

ISBN: 1-58705-120-6 Pages: 432

End-to-end QoS deployment techniques for Cisco Catalyst series switches

Examine various QoS components, including congestion management, congestion

avoidance, shaping, policing/admission control, signaling, link efficiency mechanisms, and classification and marking

Map specified class of service (CoS) values to various queues and maintain CoS values through the use of 802.1q tagging on the Cisco Catalyst 2900XL, 3500XL and Catalyst 4000 and 2948G/2980G CatOS Family of Switches

Learn about classification and rewrite capabilities and queue scheduling on the Cisco Catalyst 5000

Implement ACLs, ACPs, ACEs, and low-latency queuing on the Cisco Catalyst 2950 and 3550 Family of Switches

Understand classification, policying, and scheduling capabilities of the Catalyst 4000 and 4500 IOS Family of Switches

Configure QoS in both Hybrid and Native mode on the Catalyst 6500 Family of Switches Utilize Layer 3 QoS to classify varying levels of service with the Catalyst 6500 MSFC and Flexwan

Understand how to apply QoS in campus network designs by examining end-to-end case studies

Quality of service (QoS) is the set of techniques designed to manage network resources. QoS refers to the capability of a network to provide better service to selected network traffic over various LAN and WAN technologies. The primary goal of QoS is to provide flow priority, including dedicated bandwidth, controlled jitter and latency (required by some interactive and delay-sensitive traffic), and improved loss characteristics.

While QoS has become an essential technology for those organizations rolling out a new

Dans le document classification and marking (Page 154-157)