at the point where the traffic entered the campus network. Ideally, the trust boundary exists at the first switch receiving traffic from a device or IP phone. It is also acceptable to establish the trust boundary where all the traffic from an access switch enters a Building Distribution layer port. Note: Best practices suggest classifying and marking traffic as close to the traffic source as possible.

Content 7.2 Accommodating Voice Traffic on Campus Switches 7.2.4 Configuring a Switch for the Attachment of a Cisco Phone Figure illustrates a typical switch-phone-PC topology. Several commands are used to configure and verify basic features for managing voice traffic on Cisco Catalyst switch ports. Figure provides descriptions for the commands used to manage voice traffic.

Content 7.2 Accommodating Voice Traffic on Campus Switches 7.2.5 Basic Switch Commands to Support Attachment of a Cisco IP Phone Several commands are used to configure and verify the basic required functions on a switch port connected to an IP phone with a PC connected to that phone. An example configuration is illustrated in Figure .

Content 7.2 Accommodating Voice Traffic on Campus Switches 7.2.6 What is AutoQoS VoIP? AutoQoS gives customers the ability to deploy QoS features for converged IP telephony and data networks much faster and more efficiently. AutoQoS simplifies and automates the Modular QoS CLI (MQC) definition of traffic classes and the creation and configuration of traffic policies. AutoQoS generates traffic classes and policy map CLI templates. When AutoQoS is configured at the interface, the traffic receives the required QoS treatment automatically. In-depth knowledge of the underlying technologies, service policies, link efficiency mechanisms, and Cisco QoS best practice recommendations for voice requirements is not required to configure AutoQoS. AutoQoS can be extremely beneficial for the following scenarios:

Small- to medium-sized businesses that must deploy IP telephony quickly but lack the experience and staffing to plan and deploy IP QoS services
Large customer enterprises that need to deploy Cisco telephony solutions on a large scale, while reducing the costs, complexity, and timeframe for deployment, and ensuring that the appropriate QoS for voice applications is being set in a consistent fashion
International enterprises or service providers requiring QoS for VoIP where little expertise exists in different regions of the world and where provisioning QoS remotely and across different time zones is difficult
Service providers requiring a template-driven approach to delivering managed services and QoS for voice traffic to large numbers of customer premise devices

Cisco AutoQoS simplifies and shortens the QoS deployment cycle. AutoQoS helps in all five major aspects of successful QoS deployments :

Application classification: AutoQoS leverages intelligent classification on routers using Cisco network-based application recognition (NBAR) to provide stateful packet inspection. AutoQoS relies on CDP to ensure that the device attached to the LAN is really a Cisco IP phone. Once an IP phone is identified, the voice traffic is automatically classified and QoS policies are applied.
Policy generation: AutoQoS evaluates the network environment and generates an initial policy. It automatically generates interface configurations, policy maps, class maps, and ACLs. AutoQoS VoIP automatically employs Cisco NBAR to classify voice traffic, and mark the traffic with the appropriate DSCP value. It can be instructed to rely on, or trust, the DSCP markings previously applied to the packets.
Configuration: With one command, AutoQoS configures the port to prioritize voice traffic without affecting other network traffic, while still offering the flexibility to adjust QoS settings for unique network requirements. It also disables QoS settings when a Cisco IP Phone is relocated or moved to prevent malicious activity.
Monitoring and reporting: AutoQoS provides visibility into the classes of service deployed via system logging and Simple Network Management Protocol (SNMP) traps, with notification of abnormal events (that is, VoIP packet drops).
Consistency: Deployed QoS configurations are consistent among router and switch platforms, ensuring seamless QoS operation and interoperability within the network.

Content 7.2 Accommodating Voice Traffic on Campus Switches 7.2.7 Configuring AutoQoS VoIP on a Cisco Catalyst Switch When the AutoQoS feature is enabled on the first interface, QoS is globally enabled (mls qos global configuration command). When the auto qos voip trust interface configuration command is entered, the ingress classification on the interface is set to trust the CoS QoS label received in the packet, and the egress queues on the interface are reconfigured. QoS labels in ingress packets are trusted. When the auto qos voip cisco-phone interface configuration command is entered, the trusted boundary feature is enabled. The trusted boundary feature uses CDP to detect the presence or absence of a Cisco IP Phone. When a Cisco IP Phone is detected, the ingress classification on the interface is set to trust the QoS label received in the packet. When a Cisco IP Phone is absent, the ingress classification is set to not trust the QoS label in the packet. The egress queues on the interface are also reconfigured. This command extends the trust boundary if an IP Phone is detected. To display the initial AutoQoS configuration, use the show auto qos [interface [interface-id]] privileged EXEC command. To display any user changes to that configuration, use the show running-config privileged EXEC command. You can compare the output of the show auto qos and show running-config commands to identify the user-defined QoS settings. AutoQoS performs the following functions in a LAN :

Enforces the trust boundary on Cisco Catalyst switch access ports, and uplinks and downlinks
Enables Cisco Catalyst strict priority queuing (also known as expedited queuing) with weighted round robin (WRR) scheduling for voice and data traffic, where appropriate
Configures queue admission criteria (maps CoS values in incoming packets to the appropriate queues)
Modifies queue sizes and weights where required

Content 7.3 Voice Support Lab Exercises 7.3.1 Lab 7-1 Configuring Switches for IP Telephony Support Lab Activity Lab Exercise: Lab 7-1 Configuring Switches for IP Telephony Support

Configure auto QoS to support IP phones
Configure CoS override for data frames
Configure the distribution layer to trust access layer QoS measures
Manually configure CoS for devices that cannot specify CoS (camera)
Configure HSRP for voice and data VLANS to ensure redundancy
Configure 802.1Q trunks and EtherChannels for Layer 2 redundancy and load balancing

Content Summary When you are implementing a VoIP network, you must address quality of service (QoS), power, and capacity planning considerations. One of the easiest ways to deal with QoS is to implement the AutoQoS features. In addition, using auxiliary VLANs and inline power eases the implementation of the VoIP network. This module highlighted the issues related to implementing a VoIP network, and the initial steps to take to ensure that the VoIP network works correctly.