Catalyst 6500 Release 12.2SX Software Configuration Guide

Using AutoQoS

This chapter describes how to use the automatic quality of service (QoS) configuration feature. Release 12.2(33)SXH and later releases support the automatic quality of service (QoS) configuration feature.

Note For complete syntax and usage information for the commands used in this chapter, see the Cisco IOS Master Command List, at this URL:

http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html

Tip For additional information about Cisco Catalyst 6500 Series Switches (including configuration examples and troubleshooting information), see the documents listed on this page:

http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html

Participate in the Technical Documentation Ideas forum

This chapter consists of these sections:

•Understanding AutoQoS

•Using AutoQoS

Understanding AutoQoS

AutoQoS is a macro that applies the recommended Architecture for Voice, Video, and Integrated Data (AVVID) QoS settings to a port. These sections describe how autoQoS works:

•AutoQoS Support for a Cisco IP Phone

•AutoQoS Support for Cisco IP Communicator

•AutoQoS Support for Marked Traffic

AutoQoS Support for a Cisco IP Phone

Cisco IP phones are usually connected directly to ports. Optionally, you can attach a PC to the phone and use the phone as a hop to the switch.

The traffic that comes from the phone can be marked with an 802.1Q or 802.1p tag. The tag contains a VLAN ID and CoS value. When you configure the port to trust the CoS value that comes from the phone, the switch uses the CoS value to prioritize the phone traffic.

There is a three-port switch built into Cisco IP phones that forwards the traffic that comes from the PC, the phone, and the switch port. Cisco IP phones have trust and classification capabilities that you need to configure (see the "Configuring Cisco IP Phone Support" section).

AutoQoS supports Cisco IP phones with the auto qos voip cisco-phone interface configuration command. When you enter the auto qos voip cisco-phone interface configuration command on a port that is configured to support an IP phone and to which an IP phone is connected, the autoQoS feature does the following:

•If QoS was not already enabled, enables QoS globally.

•If VLAN-based QoS was configured for the port, reverts to the default port-based QoS (done for all ports on switching modules with 1p1q0t/1p3q1t ports).

•Sets the port trust state to trust CoS.

•Creates and applies a trust-CoS QoS policy to ports on switching modules with non-Gigabit Ethernet 1q4t/2q2t ports, which do not support port trust.

AutoQoS Support for Cisco IP Communicator

The Cisco IP Communicator program runs on a PC and emulates a Cisco IP phone. The Cisco IP Communicator marks its voice traffic with a DSCP value instead of a CoS value. When you configure the port to trust the DSCP value that comes from the Cisco IP Communicator, the switch uses the DSCP value to prioritize the Cisco IP Communicator traffic.

AutoQoS supports the Cisco IP Communicator program with the auto qos voip cisco-softphone interface configuration command. When you enter the auto qos voip cisco-softphone interface configuration command on a port that is connected to a device running the Cisco IP Communicator program, the autoQoS feature does the following:

•If QoS was not already enabled, enables QoS globally.

•If VLAN-based QoS was configured for the port, reverts to the default port-based QoS (done for all ports on switching modules with 1p1q0t/1p3q1t ports).

•If a trust state was configured for the port, reverts to the default untrusted state.

•Creates and applies ingress policers to trust DSCP 46 and remark DSCP 26 packets to DSCP 24. Packets with other DSCP values or out-of-profile packets are remarked with DSCP 0.

AutoQoS Support for Marked Traffic

Ports that connect to the interior of your network might receive traffic that has already been marked with QoS labels that are consistent with your network QoS policies, and which do not need to be changed. You can use the QoS trust feature to process the marked traffic using the received QoS values.

AutoQoS supports marked traffic with the auto qos voip trust interface configuration command. When you enter the auto qos voip trust interface configuration command, the autoQoS feature does the following:

•If QoS was not already enabled, enables QoS globally.

•If VLAN-based QoS was configured for the port, reverts to the default port-based QoS (done for all ports on switching modules with 1p1q0t/1p3q1t ports).

•If the port is configured with the switchport command, sets the port trust state to trust CoS.

•If the port is not configured with the switchport command, sets the port trust state to trust DSCP.

•Creates and applies a trust-CoS or trust-DSCP QoS policy to ports on switching modules with non-Gigabit Ethernet 1q4t/2q2t ports, which do not support port trust.

Using AutoQoS

These sections describe how to use autoQoS:

•AutoQoS Configuration Guidelines and Restrictions

•Configuring AutoQoS

AutoQoS Configuration Guidelines and Restrictions

These sections provide the configuration guidelines and restrictions for autoQoS:

•AutoQoS generates commands for the port and adds the generated commands to the running configuration.

•The generated QoS commands are applied as if you were entering them from the CLI. An existing configuration might cause the application of the generated commands to fail or an existing configuration might be overridden by the generated commands. These actions occur without warning. If the generated commands are successfully applied, any configuration that was not overridden remains in the running configuration. Any commands that were overridden might still exist in the startup-config file.

•Some of the generated commands are the type of PFC QoS commands that are applied to all ports controlled by a port ASIC. When one of these commands is applied, PFC QoS displays the messages caused by application of the command to all the ports controlled by the port ASIC. Depending on the module, these commands are applied to as many as 48 ports. See the "Number of port groups" and "Port ranges per port group" listed for each module in the Release Notes for Cisco IOS Release 12.2SX.

•You might not be able to configure support for Cisco IP phones and the other autoQoS options on ports that are controlled by the same port ASIC because of conflicting port trust state requirements.

•If application of the generated commands fails, the previous running configuration is restored.

•Enable autoQoS before you configure other QoS commands. If necessary, you can modify the QoS configuration after the autoQoS configuration completes.

•AutoQoS cannot attach a policy map to an interface if there is already a policy map attached.

•Do not modify a policy map or class map that includes AUTOQOS in its name.

•You cannot configure autoQoS on the following:

–Port-channel interfaces

–VLAN interfaces (also known as switch virtual interfaces or SVIs)

–Tunnel interfaces

–Loopback interfaces

–Subinterfaces on any type of interface

Configuring AutoQoS

AutoQoS generates commands that are appropriate for the QoS port architecture of the port on which you enter an auto qos voip command. For each of the different auto qos voip commands, autoQoS generates different QoS commands for each of these QoS port architectures:

•1p1q0t/1p3q1t

•1p1q4t/1p2q2t

•1p1q4t/1p3q8t

•1p1q8t/1p2q1t

•1q2t/1p2q2t

•1q2t/1p3q8t

•1q4t/2q2t

•1q8t/1p3q8t

•1q8t/1p7q8t

•2q8t/1p3q8t

•8q4t/1p7q4t

•8q8t/1p7q8t

The procedures in the following sections include the commands that you need to enter to display the generated commands, but the specific commands that autoQoS generates are not listed in this document. These sections describe how to configure autoQoS:

•Configuring AutoQoS Support for a Cisco IP Phone

•Configuring AutoQoS Support for Cisco IP Communicator

•Configuring AutoQoS Support for Marked Traffic

Configuring AutoQoS Support for a Cisco IP Phone

Note Complete the configuration procedures in the "Configuring Cisco IP Phone Support" section before you configure autoQoS for a Cisco IP phone.

To configure autoQoS for a Cisco IP phone, perform this task:

When configuring autoQoS for a Cisco IP phone, note the following information:

•To disable autoQoS on an interface, use the no auto qos voip interface configuration command.

Note The no auto qos voip interface configuration command does not disable QoS globally or delete the received CoS to internal DSCP map created by autoQoS.

•You might see messages that instruct you to configure other ports to trust CoS. You must do so to enable the autoQoS generated commands.

This example shows how to enable autoQoS on Fast Ethernet interface 1/1:

Router(config)# interface fastethernet 1/1 

Router(config-if)# auto qos voip cisco-phone 

Configuring AutoQoS Support for Cisco IP Communicator

To configure autoQoS for Cisco IP Communicator, perform this task:

When configuring autoQoS for Cisco IP Communicator, note the following information:

•To disable autoQoS on an interface, use the no auto qos voip interface configuration command.

Note The no auto qos voip interface configuration command does not disable QoS globally or delete the policy, class, and DSCP markdown maps created by autoQoS.

•You cannot configure support for Cisco IP Communicator on ports that are configured with the switchport keyword.

•PFC QoS supports 1023 aggregate policers and each use of the auto qos voip cisco-softphone command on a port uses two aggregate policers.

This example shows how to enable autoQoS on Fast Ethernet interface 1/1:

Router(config)# interface fastethernet 1/1 

Router(config-if)# auto qos voip cisco-softphone 

Configuring AutoQoS Support for Marked Traffic

To configure autoQoS for marked traffic, perform this task:

When configuring autoQoS to trust marked traffic, note the following information:

•To disable autoQoS on an interface, use the no auto qos voip interface configuration command.

Note The no auto qos voip interface configuration command does not disable QoS globally or delete the received CoS to internal DSCP map created by autoQoS.

•For ports configured with the switchport command, you might see messages that instruct you to configure other ports to trust CoS. You must do so to enable the autoQoS generated commands.

This example shows how to enable autoQoS on Fast Ethernet interface 1/1:

Router(config)# interface fastethernet 1/1 

Router(config-if)# auto qos voip trust 

Tip For additional information about Cisco Catalyst 6500 Series Switches (including configuration examples and troubleshooting information), see the documents listed on this page:

http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.html

Participate in the Technical Documentation Ideas forum