Configure QoS Let's review the steps to configuring QoS on a Cisco router. Step 1: Define the traffic You must tell the router which traffic you want to give QoS, which you can accomplish either using an access control list (ACL) or using Network Based Application Recognition (NBAR). An ACL is the traditional way to define any traffic for a router. With NBAR, however, the router just recognizes the traffic traveling through the router—it knows that HTTP is HTTP, Skype is Skype, etc. But there's a limited list of protocols and applications that the router recognizes. While the router won't recognize every single application, each IOS upgrade adds more to the list. In addition, you can create custom application recognition files. Step 2: Create a class-map A class-map defines the traffic into groups. For example, you could create a class-map called VoIP traffic and put all VoIP protocols under it. Step 3: Create a policy-map A policy-map matches the classes from the class-map with how much bandwidth and/or priority you want to give this traffic. Step 4: Apply the policy-map to the interface Like an ACL, you must apply the policy-map to the specific interface you want it to affect. You can apply the policy-map in either output or input mode. Here's the command to use: service-policy output|input {name of policy-map}If you're using NBAR to recognize the traffic, you must also use the ip nbar protocol-discovery command on the interface. This enables NBAR to begin looking at the traffic. Download the QoS template Now that you know the basic steps to configuring QoS, you can get started with our downloadable QoS template. (This is the same template that TechRepublic's George Ou has used to explain how to configure the Cisco 871W router for basic configurations, advanced 871W configurations, and an IPSec site-to-site VPN.) Follow these steps: Download the template. Open the Excel file, and fill out the yellow sections on the Variables worksheet. Click the Replace button; it will generate the appropriate QoS configuration on a new sheet called QOS-1. Copy the configuration from the Excel file, and paste it into the Cisco CLI. You can copy directly from Excel into a Telnet or SSH session or even the console port. --------------------------------------------------- Here is a template <pre> Access-list 150 Permit TCP any any eq !Critical Ports Access-list 151 Permit TCP any any eq !Less Critical Ports Class-map match-all CRITICAL Match access-group 150 Class-map match-all LESSCRITICAL Match access-group 151 Policy-map QoS Class CRITICAL Priority Percent 50 Class LESSCRITICAL Priority Percent 49 Class class-default set dscp default Fair-queue random-detect Interface FA 3/23 Service-policy output QoS</pre>

Configure QoS Let's review the steps to configuring QoS on a Cisco router. Step 1: Define the traffic You must tell the router which traffic you want to give QoS, which you can accomplish either using an access control list (ACL) or using Network Based Application Recognition (NBAR). An ACL is the traditional way to define any traffic for a router. With NBAR, however, the router just recognizes the traffic traveling through the router—it knows that HTTP is HTTP, Skype is Skype, etc. But there's a limited list of protocols and applications that the router recognizes. While the router won't recognize every single application, each IOS upgrade adds more to the list. In addition, you can create custom application recognition files. Step 2: Create a class-map A class-map defines the traffic into groups. For example, you could create a class-map called VoIP traffic and put all VoIP protocols under it. Step 3: Create a policy-map A policy-map matches the classes from the class-map with how much bandwidth and/or priority you want to give this traffic. Step 4: Apply the policy-map to the interface Like an ACL, you must apply the policy-map to the specific interface you want it to affect. You can apply the policy-map in either output or input mode. Here's the command to use: service-policy output|input {name of policy-map}If you're using NBAR to recognize the traffic, you must also use the ip nbar protocol-discovery command on the interface. This enables NBAR to begin looking at the traffic. Download the QoS template Now that you know the basic steps to configuring QoS, you can get started with our downloadable QoS template. (This is the same template that TechRepublic's George Ou has used to explain how to configure the Cisco 871W router for basic configurations, advanced 871W configurations, and an IPSec site-to-site VPN.) Follow these steps: Download the template. Open the Excel file, and fill out the yellow sections on the Variables worksheet. Click the Replace button; it will generate the appropriate QoS configuration on a new sheet called QOS-1. Copy the configuration from the Excel file, and paste it into the Cisco CLI. You can copy directly from Excel into a Telnet or SSH session or even the console port. --------------------------------------------------- Here is a template <pre> Access-list 150 Permit TCP any any eq !Critical Ports Access-list 151 Permit TCP any any eq !Less Critical Ports Class-map match-all CRITICAL Match access-group 150 Class-map match-all LESSCRITICAL Match access-group 151 Policy-map QoS Class CRITICAL Priority Percent 50 Class LESSCRITICAL Priority Percent 49 Class class-default set dscp default Fair-queue random-detect Interface FA 3/23 Service-policy output QoS</pre>