Qos books download

What we can do with QoS however, is influence the queuing delay. For example, you could create a priority queue that is always served before other queues. Jitter is the variation of one-way delay in a stream of packets. Because of congestion in the network, some packets are delayed. The delay between packet 1 and 2 is 20 ms, the delay between packet 2 and 3 is 40 ms, the delay between packet 3 and 4 is 5 ms, etc. The receiver of these voice packets must deal with jitter, making sure the packets have a steady delay or you will experience poor voice quality.

Loss is the amount of lost data, usually shown as a percentage of lost packets sent. Packet loss is always possible. For example, when there is congestion, packets will be queued but once the queue is full…packets will be dropped. With QoS, we can at least decide which packets get dropped when this happens. With QoS, we can change our network so that certain traffic is preferred over other traffic when it comes to bandwidth, delay, jitter and loss. What you need to configure however really depends on the applications that you use.

Perhaps the latest IOS image:. The file is Bandwidth is nice to have, it makes the difference between having to wait a few seconds, minutes or a few days to download a file like this.

What about delay? There is a one-way delay to get the data from the server to your computer. When you click on the download link, it might take a short while before the download starts. You are not interacting with the download, just waiting for it to complete.

What about packet loss? File transfers like these use TCP and when some packets are lost, TCP will retransmit your data, making sure the download makes it completely to your computer.

An application like your web browser that downloads a file is a non-interactive application , often called a batch application or batch transfer. Bandwidth is nice to have since it reduces the time to wait for the download to complete. With QoS, we can assign enough bandwidth to applications like these to ensure downloads complete in time and reducing packet loss to a minimum to prevent retransmissions.

Another type of application is the interactive application. A good example is when you use telnet or SSH to access your router or switch:.

Since you are typing commands and waiting for a response, a high delay can be annoying to work with. Satellite links can have a one-way delay of between ms which means that when you type a few characters, there will be a short pause before you see the characters appear on your console. With QoS, we can ensure that in case of congestion, interactive applications are served before bandwidth-hungry batch applications.

First, let me give you a quick overview of how VoIP works:. Above we have a user that is speaking. With VoIP, we use a codec that processes the analog sound into a digital signal. The analog sound is digitized for a certain time period which is usually 20 ms. With the G codec, each 20 ms of audio is bytes of data.

Cisco IOS software can classify packets and apply the appropriate QoS service before the data is encrypted and tunneled. The QoS for VPN feature allows users to look inside the packet so that packet classification can be done based on original port numbers and based on source and destination IP addresses. This allows the service provider to treat mission critical or multi-service traffic with higher priority across their network. The QoS policy on a DMVPN hub on a per-tunnel instance lets you shape tunnel traffic to individual spokes a parent policy and differentiate individual data flows going through the tunnel for policing a child policy.

Although you can configure many spokes into the same NHRP group, the tunnel traffic for each spoke is measured individually for shaping and policing. You can use the auto-QoS feature to simplify the deployment of QoS features.

Auto-QoS determines the network design and enables QoS configurations so that the router can prioritize different traffic flows. It uses the ingress and egress queues instead of using the default disabled QoS behavior. The switch offers best-effort service to each packet, regardless of the packet contents or size, and sends it from a single queue.

When you enable auto-QoS, it automatically classifies traffic based on the traffic type and ingress packet label. The switch uses the classification results to choose the appropriate egress queue.

For more information about configuring Auto QoS, see the following link:. Skip to content Skip to search Skip to footer. Book Contents Book Contents. Find Matches in This Book. PDF - Complete Book 1. Updated: February 6, Chapter: Configuring QoS. For example, you could set the precedence bit and the CoS for all conforming packets.

A submode for an action configuration could then be provided by the policing feature. In this example, the exceed-markdown-table and violate-mark-down-table are table maps. Only one markdown table map is allowed for each marking field in the device. The following example displays a VLAN policer configuration. The policing unit is the basis on which the token bucket works. The burst parameters are specified in bytes. This is the default mode; it is the unit that is assumed when no units are specified.

The CIR and PIR can also be configured in percent, in which case the burst parameters have to be configured in milliseconds. The following is an example of a policer configuration in bits per second.

In this configuration, a dual-rate three-color policer is configured where the units of measurement is bits. The burst and peak burst are all specified in bits. Policer based markdown actions are only supported using table maps.

The following steps and examples show how to use table map marking for your QoS configuration:. Define the table-map using the table-map command and indicate the mapping of the values. This table does not know of the policies or classes within which it will be used. In the example, a table map named table-map1 is created. The mapping defined is to convert the value from 0 to 1 and from 2 to 3, while setting the default value to 4. The following example shows how to use table maps to retain CoS markings on an interface for your QoS configuration.

The cos-trust-policy policy configured in the example is enabled in the ingress direction to retain the CoS marking coming into the interface.

If the policy is not enabled, only the DSCP is trusted by default. If a pure Layer 2 packet arrives at the interface, then the CoS value will be rewritten to 0 when there is no such policy in the ingress port for CoS. Review the auto-QoS documentation to see if you can use these automated capabilities for your QoS configuration. To help you research and resolve system error messages in this release, use the Error Message Decoder tool.

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

Access to most tools on the Cisco Support website requires a Cisco. This table provides release and related information for features explained in this module. These features are available on all releases subsequent to the one they were introduced in, unless noted otherwise.

QoS provides preferential treatment to specific types of traffic at the expense of other traffic types. Use Cisco Feature Navigator to find information about platform and software image support. Skip to content Skip to search Skip to footer. Book Contents Book Contents. Find Matches in This Book.

PDF - Complete Book 2. Updated: January 6, Chapter: Configuring QoS. Understanding of QoS implementation. QoS Terminology The following terms are used interchangeably in this QoS configuration guide: Upstream direction towards the device is the same as ingress.

Downstream direction from the device is the same as egress. Information About QoS QoS Overview By configuring the quality of service QoS , you can provide preferential treatment to specific types of traffic at the expense of other traffic types. Table 1. Supported number of queues at port level Up to 8 queues supported on a port. HQoS allows you to perform: Hierarchical classification— Traffic classification is based upon other classes. Note Hierarchical shaping is only supported for the port shaper, where for the parent you only have a configuration for the class default, and the only action for the class default is shaping.

QoS Implementation Typically, networks operate on a best-effort delivery basis, which means that all traffic has equal priority and an equal chance of being delivered in a timely manner. Figure 1. End-to-End QoS Solution Using Classification All switches and routers that access the Internet rely on the class information to provide the same forwarding treatment to packets with the same class information and different treatment to packets with different class information.

Packet Classification Packet classification is the process of identifying a packet as belonging to one of several classes in a defined policy, based on certain criteria. The policy class language is used to define the following: Class-map template with one or several match criteria Policy-map template with one or several classes associated to the policy map The policy map template is then associated to one or several interfaces on the device.

Packet classification can be categorized into the following types: Classification based on information that is propagated with the packet Classification based on information that is device specific Hierarchical classification Classification Based on Information That is Propagated with the Packet Classification Based on Information that is Device Specific Hierarchical Classification Classification Based on Information That is Propagated with the Packet Classification that is based on information that is part of the packet and propagated either end-to-end or between hops, typically includes the following: Classification based on Layer 3 or 4 headers Classification based on Layer 2 information Classification Based on Layer 3 or Layer 4 Header Classification Based on Layer 2 Header Classification Based on Layer 3 or Layer 4 Header This is the most common deployment scenario.

Table 2. Some fields in Layer 2 header can also be set uing a policy. Classification Based on Layer 2 Header A variety of methods can be used to perform classification based on the Layer 2 header information. The most common methods include the following: MAC address-based classification only for access groups —Classification is based upon the source MAC address for policies in the input direction and destination MAC address for policies in the output direction.

Note Some of these fields in the Layer 2 header can also be set using a policy. Classification Based on Information that is Device Specific The device also provides classification mechanisms that are available where classification is not based on information in the packet header or payload. Hierarchical Classification The device permits you to perform a classification based on other classes. Egress Port Activity The following activities occur at the egress port of the device : Policing—Policing determines whether a packet is in or out of profile by comparing the rate of the incoming traffic to the configured policer.

Classification Classification is the process of distinguishing one kind of traffic from another by examining the fields in the packet. In the QoS context, the permit and deny actions in the access control entries ACEs have different meanings from security ACLs: If a match with a permit action is encountered first-match principle , the specified QoS-related action is taken. Note When creating an access list, note that by default the end of the access list contains an implicit deny statement for everything if it did not find a match before reaching the end.

Class Maps A class map is a mechanism that you use to name a specific traffic flow or class and isolate it from all other traffic. Note You cannot configure IPv4 and IPv6 classification criteria simultaneously in the same class-map.

Policy Maps A policy map specifies which traffic class to act on. Actions can include the following: Setting a specific DSCP or IP precedence value in the traffic class Setting a CoS value in the traffic class Setting a QoS group Specifying the traffic bandwidth limitations and the action to take when the traffic is out of profile Before a policy map can be effective, you must attach it to a port.

Note You cannot configure both priority and set for a policy map. If both these commands are configured for a policy map, and when the policy map is applied to an interface, error messages are displayed. A policy map also has these characteristics: A policy map can contain multiple class statements, each with different match criteria and policers.

Note All traffic, regardless of whether it is bridged or routed, is subjected to a policer, if one is configured. You can only configure policing on a physical port. Marking Marking is used to convey specific information to a downstream device in the network, or to carry information from one interface in a device to another. Switch Specific Information Marking This form of marking includes marking of fields in the packet data structure that are not part of the packets header, so that the marking can be used later in the data path.

Table Map Marking Table map marking enables the mapping and conversion from one field to another using a conversion table. The following table shows the currently supported forms of mapping: Table 3. Rewrite—Packets coming in are rewritten depending upon the configured table map.

Mapping—Table map based policies can be used instead of set policies. The following steps are required for table map marking: Define the table map—Use the table-map global configuration command to map the values. Define the policy map—You must define the policy map where the table map will be used. Associate the policy to an interface.

Note A table map policy on an input port changes the trust setting of that port to the from type of qos-marking. Traffic Conditioning To support QoS in a network, traffic entering the service provider network needs to be policed on the network boundary routers to ensure that the traffic rate stays within the service limit.

Note When running QoS tests on network traffic, you may see different results for the shaper and policing data. This table compares the policing and shaping functions. Table 4. Smooths traffic and sends it out at a constant rate. When tokens are exhausted, action is taken immediately. Shaping has only one unit of configuration - in bits per second. Shaping does not have the provision to mark packets that do not meet the profile. Works for both input and output traffic.

Implemented for output traffic only. Policing Shaping Policing The QoS policing feature is used to impose a maximum rate on a traffic class. The following policing forms or policers are supported for QoS: Single-rate two-color policing Dual-rate three-color policing Note Single-rate three-color policing is not supported. Note For information about the token-bucket algorithm, see Token-Bucket Algorithm. Dual-Rate Three-Color Policing With the dual rate policer, the device supports only color-blind mode.

The following shaping forms are supported in a class: Average rate shaping Hierarchical shaping Shaping is implemented using a token bucket. Hierarchical Shaping Shaping can also be configured at multiple levels in a hierarchy. There are two supported types of hierarchical shaping: Port shaper User-configured shaping The port shaper uses the class default and the only action permitted in the parent is shaping. Queuing and Scheduling The device uses both queuing and scheduling to help prevent traffic congestion.

The device supports the following queuing and scheduling features: Bandwidth Weighted Tail Drop Priority queues Queue buffers Weighted Random Early Detection When you define a queuing policy on a port, control packets are mapped to the best priority queue with the highest threshold. Control packets queue mapping works differently in the following scenarios: Without a quality of service QoS policy—If no QoS policy is configured, control packets with DSCP values 16, 24, 48, and 56 are mapped to queue 0 with the highest threshold of threshold2.

Note Queuing policy in egress direction does not support match access-group classification. Control traffic is redirected to the best queue based on the following rules: If defined in a user policy, the highest- level priority queue is always chosen as the best queue.

Note To provide proper QoS for Layer 3 packets, you must ensure that packets are explicitly classified into appropriate queues. Bandwidth Weighted Tail Drop Priority Queues Queue Buffer Bandwidth The supports the following bandwidth configurations: Bandwidth percent Bandwidth remaining ratio Bandwidth Percent Bandwidth Remaining Ratio Bandwidth Percent You can use the bandwidth percent policy-map class command to allocate a minimum bandwidth to a particular class.

Note A queue can oversubscribe bandwidth in case the other queues do not utilize the entire port bandwidth. Bandwidth Remaining Ratio You use the bandwidth remaining ratio policy-map class command to create a ratio for sharing unused bandwidth in specified queues.

Weighted Tail Drop The egress queues use an enhanced version of the tail-drop congestion-avoidance mechanism called weighted tail drop WTD. Figure 2. WTD and Queue Operation. The following figure shows an example of WTD operating on a queue whose size is frames. Three drop percentages are configured: 40 percent frames , 60 percent frames , and percent frames. These percentages indicate that up to frames can be queued at the percent threshold, up to frames at the percent threshold, and up to frames at the percent threshold.

The following are the WTD threshold default values: Table 5. If 2 WTD thresholds are configured, then the maximum value percentage will be Priority Queues Each port supports eight egress queues, of which two can be given a priority.

Note You can configure a priority only with a level. Queue Buffer At boot time, when there is no policy map enabled on the wired port, there are two queues created by default. The following table shows which packets go into which one of the queues: Table 6. Note By default, Queue 0 is not a priority queue. Queue Buffer Allocation Dynamic Threshold and Scaling Queue Buffer Allocation The buffer allocation to any queue can be tuned using the queue-buffers ratio policy-map class configuration command.

Dynamic Threshold and Scaling Traditionally, reserved buffers are statically allocated for each queue. Trust Behavior for Wired Ports For wired ports that are connected to the device end points such as IP phones, laptops, cameras, telepresence units, or other devices , their DSCP, precedence, or CoS values coming in from these end points are trusted by the device and therefore are retained in the absence of any explicit policy configuration.

Table 7. Table 8. Table 9. Table The following are restrictions for applying QoS features on the device for the wired target: A maximum of 8 queuing classes are supported on the device port for the wired target.

A maximum of policy-maps can be created. No more than two levels are supported in a QoS hierarchy. A QoS policy cannot be attached to any EtherChannel interface. Policing in both the parent and child is not supported in a QoS hierarchy. Marking in both the parent and child is not supported in a QoS hierarchy.

The actions under a policer within a policy map have the following restrictions: The conform action must be transmit. The markdown types must be the same within a policy. Only marking policy is supported on SVI. Classification counters have the following specific restrictions: Classification counters count packets instead of bytes. Filter-based classification counters are not supported Only QoS configurations with marking or policing trigger the classification counter.

For ports with wired targets, these are the only supported hierarchical policies: Police chaining in the same policy is unsupported. The child filter type must match the parent filter type with the following exceptions: If the parent class is configured to match IP, then the child class can be configured to match the ACL. The following are restrictions for applying QoS features on the VLAN to the wired target: For a flat or nonhierarchical policy, only marking or a table map is supported. The following are restrictions and considerations for applying QoS features on EtherChannel and channel member interfaces: QoS is not supported on an EtherChannel interface.

Auto QoS is not supported on EtherChannel members. Note On attaching a service policy to an EtherChannel, the following message appears on the console: ' Warning: add service policy will cause inconsistency with port xxx in ether channel xxx. This warning message should be expected.

This warning message is a reminder to attach the same policy to other ports in the same EtherChannel. The same message will be seen during boot up. This message does not mean there is a discrepancy between the EtherChannel member ports. How to Configure QoS Configuring Class, Policy, and Maps Creating a Traffic Class To create a traffic class containing match criteria, use the class-map command to specify the traffic class name, and then use the following match commands in class-map configuration mode, as needed.

Before you begin All match commands specified in this configuration task are considered optional, but you must configure at least one match criterion for a class. Procedure Command or Action Purpose Step 1 configure terminal Example: configure terminal Enters the global configuration mode. Note This is the default. Enters up to 4 CoS values separated by spaces 0 to 7.

Note Since CPU generated packets are not marked at egress, the packet will not match the configured class-map. Step 7 match qos-group qos group value Example: config-cmap match qos-group 10 config-cmap Optional Matches QoS group value from 0 to Step 9 end Example: config-cmap end Saves the configuration changes.

What to do next Configure the policy map. Creating a Traffic Policy To create a traffic policy, use the policy-map global configuration command to specify the traffic policy name. The following policy map class-actions are supported: bandwidth—Bandwidth configuration options. Before you begin You should have first created a class map. You can also create a system default class for unclassified packets.

Step 5 exit Example: config-pmap-c exit config-pmap-c Optional Exits from QoS class action configuration mode. Step 6 no Example: config-pmap-c no config-pmap-c Optional Negates the command. Step 8 priority level level value Example: config-pmap-c priority level 1 config-pmap-c Optional Sets the strict scheduling priority for this class.

Command options include: level —Establishes a multi-level priority queue. Step 9 queue-buffers ratio ratio limit Example: config-pmap-c queue-buffers ratio 10 config-pmap-c Optional Configures the queue buffer for the class. Step 14 end Example: config-pmap-c end config-pmap-c Saves the configuration changes. What to do next Configure the interface. Step 2 policy-map policy name Example: config policy-map policy1 config-pmap Enters policy map configuration mode.

Step 3 class class name Example: config-pmap class class1 config-pmap-c Enters policy class map configuration mode. Command options for policy class map configuration mode include the following: bandwidth —Bandwidth configuration options.

Note This procedure describes the available configurations using set command options. You can also set the following values using the set cos command: cos table —Sets the CoS value based on a table map.

You can set the following values using the set ip dscp command: dscp value —Sets a specific DSCP value. You can set the following values using the set ip precedence command: precedence value —Sets the precedence value from 0 to 7. You can set the following values using the set precedence command: precedence value —Sets the precedence value from 0 to 7. You can set the following values using this command: qos-group value —A number from 1 to Step 9 end Example: config-pmap end Saves configuration changes.

Step 10 show policy-map Example: show policy-map Optional Displays policy configuration information for all classes configured for all service policies. What to do next Attach the traffic policy to an interface using the service-policy command. Attaching a Traffic Policy to an Interface After the traffic class and traffic policy are created, you must use the service-policy interface configuration command to attach a traffic policy to an interface, and to specify the direction in which the policy should be applied either on packets coming into the interface or packets leaving the interface.

Before you begin A traffic class and traffic policy must be created before attaching a traffic policy to an interface. In this example, the traffic policy evaluates all traffic leaving that interface. Step 4 end Example: config-if end Saves configuration changes. Step 5 show policy map Example: show policy map Optional Displays statistics for the policy on the specified interface. What to do next Proceed to attach any other traffic policy to an interface, and to specify the direction in which the policy should be applied.

Classifying, Policing, and Marking Traffic on Physical Ports by Using Policy Maps You can configure a nonhierarchical policy map on a physical port that specifies which traffic class to act on.

Before you begin You should have already decided upon the classification, policing, and marking of your network traffic by policy maps prior to beginning this procedure. Step 8 exit Example: config-pmap-c exit Returns to policy map configuration mode. Step 9 exit Example: config-pmap exit Returns to global configuration mode. Step 11 service-policy input policy-map-name Example: config-if service-policy input flowit Specifies the policy-map name, and applies it to an ingress port.

Step 13 show policy-map [ policy-map-name [ class class-map-name ]] Example: show policy-map Optional Verifies your entries. Step 14 copy running-config startup-config Example: copy-running-config startup-config Optional Saves your entries in the configuration file. What to do next If applicable to your QoS configuration, configure classification, policing, and marking of traffic on SVIs by using policy maps.

Classifying, Policing, and Marking Traffic on SVIs by Using Policy Maps Before you begin You should have already decided upon the classification, policing, and marking of your network traffic by using policy maps prior to beginning this procedure. Step 3 match vlan vlan number Example: config-cmap match vlan config-cmap exit config Specifies the VLAN to match to the class map.

Step 5 description description Example: config-pmap description vlan Optional Enters a description of the policy map. Step 9 exit Example: config-pmap-c exit Returns to policy map configuration mode. Step 10 exit Example: config-pmap exit Returns to global configuration mode. Step 14 show policy-map [ policy-map-name [ class class-map-name ]] Example: show policy-map Optional Verifies your entries.

Step 15 copy running-config startup-config Example: copy-running-config startup-config Optional Saves your entries in the configuration file. Configuring Table Maps Table maps are a form of marking, and also enable the mapping and conversion of one field to another using a table. Note A table map can be referenced in multiple policies or multiple times in the same policy. In table map configuration mode, you can perform the following tasks: default : Configures the table map default value, or sets the default behavior for a value not found in the table map to copy or ignore.

Note The mapping from CoS values to DSCP values in this example is configured by using the set policy map class configuration command as described in a later step in this procedure. Step 4 exit Example: Device config-tablemap exit Device config Returns to global configuration mode. Step 6 show table-map Example: Device show table-map Table Map table01 from 0 to 2 from 1 to 4 from 24 to 3 from 40 to 6 default 0 Displays the table map configuration.

Step 7 configure terminal Example: Device configure terminal Device config Enters global configuration mode. Step 8 policy-map Example: Device config policy-map table-policy Device config-pmap Configures the policy map for the table map. Step 9 class class-default Example: Device config-pmap class class-default Device config-pmap-c Matches the class to the system default. Step 10 set cos dscp table table map name Example: Device config-pmap-c set cos dscp table table01 Device config-pmap-c If this policy is applied on input port, that port will have trust DSCP enabled on that port and marking will take place depending upon the specified table map.

What to do next Configure any additional policy maps for QoS for your network. Before you begin You should have created a class map for bandwidth before beginning this procedure. Command options for policy class map configuration mode include the following: word —Class map name.

The queue can oversubscribe bandwidth in case other queues do not utilize entire port bandwidth. The total sum cannot exceed percent. It is preferred to use this command when the priority command is used for certain queues in the policy. You can also assign ratios rather than percentages to each queue; the queues will be assigned certain weights which are inline with these ratios. Ratios can range from 0 to Total bandwidth ratio allocation for the policy in this case can exceed Note You cannot mix bandwidth types on a policy map.

Step 5 end Example: config-pmap-c end Saves configuration changes. Step 6 show policy-map Example: show policy-map Optional Displays policy configuration information for all classes configured for all service policies. Configuring Police This procedure explains how to configure policing on your. Before you begin You should have created a class map for policing before beginning this procedure.

The following police conform-action transmit exceed-action subcommand options are available: drop —Drops the packet. Note Policer-based markdown actions are only supported using table maps. Note The show policy-map command output does not display counters for conformed bytes and exceeded bytes What to do next Configure any additional policy maps for QoS for your network.

Configuring Priority This procedure explains how to configure priority on your device. The device supports giving priority to specified queues. There are two priority levels available 1 and 2.

Note Queues supporting voice and video should be assigned a priority level of 1. Before you begin You should have created a class map for priority before beginning this procedure.

Note Priority level 1 is more important than priority level 2. Configuring Queues and Shaping Configuring Egress Queue Characteristics Depending on the complexity of your network and your QoS solution, you may need to perform all of the procedures in this section.

Note You can only configure the egress queues on the device. Configuring Queue Buffers The allows you to allocate buffers to queues. Note Queue-buffer ratio cannot be configured with a queue-limit. Before you begin The following are prerequisites for this procedure: You should have created a class map for the queue buffer before beginning this procedure.

You can also assign ratios rather than a percentage to each queue; the queues will be assigned certain weights that are inline with these ratios. Note The sum of all configured buffers in a policy must be less than or equal to percent. Unallocated buffers are are evenly distributed to all the remaining queues. Ensure sufficient buffers are allocated to all queues including the priority queues. Step 6 end Example: config-pmap-c end Saves configuration changes.

Step 7 show policy-map Example: show policy-map Optional Displays policy configuration information for all classes configured for all service policies. Note You can only configure queue limits on the egress queues on wired ports.

Before you begin The following are prerequisites for this procedure: You should have created a class map for the queue limits before beginning this procedure. Note The does not support absolute queue-limit percentages. What to do next Proceed to configure any additional policy maps for QoS for your network. Configuring Shaping You use the shape command to configure shaping maximum bandwidth for a particular class.

Before you begin You should have created a class map for shaping before beginning this procedure. Command parameters include: policy map name interface session show policy-map session [ input output uid UUID ] Displays the session QoS policy.

Examples: Class of Service Layer 2 Classification This example shows how to classify packets for QoS using a class of service Layer 2 classification: configure terminal config class-map cos config-cmap match cos?

Examples: Class of Service DSCP Classification This example shows how to classify packets for QoS using a class of service DSCP classification: configure terminal config class-map dscp config-cmap match dscp af21 af22 af23 config-cmap After creating a class map by using a DSCP classification, you then create a policy map for the class, and apply the policy map to an interface for QoS.

Examples: Classification by DSCP or Precedence Values This example shows how to classify packets by using DSCP or precedence values: configure terminal config class-map prec2 config-cmap description matching precedence 2 packets config-cmap match ip precedence 2 config-cmap exit config class-map ef config-cmap description EF traffic config-cmap match ip dscp ef config-cmap After creating a class map by using a DSCP or precedence values, you then create a policy map for the class, and apply the policy map to an interface for QoS.

Examples: Hierarchical Classification The following is an example of a hierarchical classification, where a class named parent is created, which matches another class named child. Examples: Queue Buffers Configuration The following example shows how configure a queue buffer policy and then apply it to an interface for QoS: configure terminal config policy-map policy config-pmap class class config-pmap-c bandwidth remaining ratio 10 config-pmap-c queue-buffer ratio? This is an example of a policing action configuration: configure terminal config policy-map police config-pmap class class-default config-pmap-c police cir pir config-pmap-c-police conform-action transmit config-pmap-c-police exceed-action set-dscp-transmit dscp table exceed-markdown-table config-pmap-c-police violate-action set-dscp-transmit dscp table violate-markdown-table config-pmap-c-police end In this example, the exceed-markdown-table and violate-mark-down-table are table maps.

Note Policer based markdown actions are only supported using table maps. Examples: Table Map Marking Configuration The following steps and examples show how to use table map marking for your QoS configuration: Define the table map.

Note This release does not support converged access. Was this Document Helpful? Yes No Feedback. Supported targets. Configuration sequence. Supported number of queues at port level. Up to 8 queues supported on a port. Supported classification mechanism. Flash Override. Internetwork control. Network control. Some of these fields in the Layer 2 header can also be set using a policy. You cannot configure both priority and set for a policy map. QoS Group. Sends conforming traffic up to the line rate and allows bursts.

Single-rate three-color policing is not supported. You can configure a priority only with a level. Control Packets. Rest of Packets. Layer 3. Based on DSCP. Layer 2. Not applicable. Based on CoS. On attaching a service policy to an EtherChannel, the following message appears on the console: ' Warning: add service policy will cause inconsistency with port xxx in ether channel xxx. Step 1. Step 2. Enters class map configuration mode.