Table Of Contents
QoS: CBQoS Management—Policy-to-Interface Mapping Support
First Published: December 4, 2006Last Updated: December 4, 2006
The QoS: CBQoS Management—Policy-to-Interface Mapping Support feature lets you use Simple Network Management Protocol (SNMP) to find which service policy is applied to a particular interface, without having to search the entire service policy table in the CISCO-CLASS-BASED-QOS-MIB. This feature introduces the CISCO-CBP-TARGET-MIB, which stores these mappings.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for QoS: CBQoS Management—Policy-to-Interface Mapping Support" section.
Finding Support Information for Platforms and Cisco IOS and Catalyst OS Software Images
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Prerequisites for QoS: CBQoS Management—Policy-to-Interface Mapping Support
•You must enable SNMP on the label switch routers (LSRs) in your network.
•You must configure policy maps and attach them to interfaces in an input or output direction within your network.
Restrictions for QoS: CBQoS Management—Policy-to-Interface Mapping Support
•Service policies applied to PPP sessions are not supported in Cisco IOS Release 12.2(31)SB2.
•The CISCO-CBP-TARGET-MIB is limited to read-only (RO) permission for MIB objects.
•This feature is supported on Cisco 10000 series routers with performance routing engine 2 (PRE2) and 3 (PRE3).
Information About QoS: CBQoS Management—Policy-to-Interface Mapping Support
To use the QoS: CBQoS Management—Policy-to-Interface Mapping Support feature, you should understand the following concepts:
Feature Overview of QoS: CBQoS Management—Policy-to-Interface Mapping Support
To find the QoS service policies that are applied to a specific interface (more generically referred to as a target), you must search the entire cbQosServicePolicyTable within the CISCO-CLASS-BASED-QOS-MIB. This process can be very time consuming in large scale configurations, and therefore, is not feasible.
A solution was to create the CISCO-CBP-TARGET-MIB, a more generic MIB that allows any type of target to be mapped to the service policies that are applied to it.
The CISCO-CBP-TARGET-MIB maps policy targets to their corresponding attached service policies by providing a link to the policy instance (service policy) and the policy-map configuration data by using row pointers to the tables that manage each one. For policy types in the CISCO-CLASS-BASED-QOS-MIB, the CISCO-CBP-TARGET-MIB maps targets to their cbQosServicePolicyTable and cbQosPolicyMapCfgTable rows, respectively.
Figure 1 shows the relationship between the CISCO-CBP-TARGET-MIB and the CISCO-CLASS-BASED-QOS-MIB.
Figure 1 Relationship between the CISCO-CBP-TARGET-MIB and the CISCO-CLASS-BASED-QOS-MIB
CISCO-CBP-TARGET-MIB Objects and Descriptions
The CISCO-CBP-TARGET-MIB consists of the ccbptTargetTable, which describes the class-based policy attachments to specific targets.
Table 1 lists the CISCO-CBP-TARGET-MIB objects and their descriptions.
Decoding Index Values
The CISCO-CBP-TARGET-MIB contains objects that define textual conventions for representing targets that have class-based policy mappings. A target can be any logical interface or entity to which a class-based policy can be applied.
The ccbptTarget is a series of octets that should be interpreted according to the value of ccbptTargetType.
Figure 2 shows a sample index with the type genIf(1) and how to decode index values corresponding to configuration mapping data output.
Figure 2 Sample Index with Mapping Data Output
Figure 2 shows the mapping of the index portion of the object identifier (OID) for an instance of the ccbptPolicyMap object. Each portion of the index is defined as follows:Configuration Policy Mapping Data-------------------------------ccbptPolicyMap.220.127.116.11.18.104.22.168.3001 = cbQosPolicyMapName.1293
Where from left to right:
•ccbptTargetType—Value of 1 indicates the ccbptTargetType which is genIf(1). The target type indicates that the value contained in the ccbptTargetId is an ifIndex value.
•ccbptTargetId Length—Value of 4 indicates that the length of the ccbptTargetId to follow is 4 bytes. The ccbptTargetId is defined in the MIB as a variable length octet string. Representing this object in the index of a table requires that the object be preceded by the length of an octet string.
•ccbptTargetId—Value of 0.0.6.97 indicates the target ID. The length of the third index is determined by the value in the second byte of the entire index. (In this example, the length of the target ID is 4 bytes.) For supported ccbptTargetId values, see the "Possible Values for ccbptTargetId" section.
Numerical Value for the ifIndex Example
Figure 3 shows the numerical value of the ifIndex ccbptTargetId, 0.0.6.97.
Figure 3 Numerical Value for an ifIndex
•ccbptTargetDirection—Value of 3 indicates the ccbptTarget output direction.
•ccbptPolicyType—Value of 1 indicates the ccbptPolicyType, which is ciscoCbQos(1).
•ccbptPolicyId—Value of 3001 indicates the ccbptPolicyId, which is the policy index integer for the policy instance applied to the target. The value of 3001 equals the value of the cbQosPolicyIndex for the corresponding entry in the cbQosServicePolicyTable in the CISCO-CLASS-BASED-QOS-MIB.
•cbQosPolicyMapName.1293—Value indicates the row in the cbQosPolicyMapTable describing the configuration of the policy map applied to the output direction of this ccbptTargetId.
Possible Values for ccbptTargetId
Figure 4 shows the supported ccbptTargetId values.
Figure 4 ccbptTargetId Values
•For genIf(1), OCTET STRING (SIZE(4))—ifIndex (4d). Where the (4d) value is a 4-byte decimal for the length of the ccbptTargetId in the example.
•For atmPvc(2), OCTET STRING (SIZE(8))—ATM PVC (4d:2d:2d). Where the ATM PVC has a ccbptTargetId length of 8 bytes (4d:2d:2d); for example:
•For frDlci(3), OCTET STRING(SIZE(6))—Frame Relay ifIndex is the first 4 bytes, and DLCI is the last 2 bytes (4d:2d).
•For controlPlane(4), OCTET STRING(SIZE(4))—Control Plane Entity (4d).
Objects in the CISCO-CBP-TARGET-MIB
The notation used in the CISCO-CBP-TARGET-MIB follows the conventions defined in Abstract System Notation One (ASN.1). ASN.1 defines an Open System Interconnection (OSI) language used to describe data types independently from particular computer structures and presentation techniques. Each object in the MIB incorporates a DESCRIPTION field that includes an explanation of the object's meaning and usage, which, together with the other characteristics of the object (SYNTAX, MAX-ACCESS, and INDEX), provides sufficient information for management application development, as well as for documentation and testing.
A network administrator can access the entries (objects) in the CISCO-CBP-TARGET-MIB by means of any SNMP-based network management system (NMS). The network administrator can retrieve information in the CISCO-CBP-TARGET-MIB using standard SNMP get and getnext operations.
Scalar Objects in the CISCO-CBP-TARGET-MIB
The CISCO-CBP-TARGET-MIB contains the following unsupported scalar object:
•ccbptPolicyNext—Indicates the next available value of ccbptPolicyId that can be used to create a new conceptual row in the ccbptTargetTable. If no available identifier exists, this object has a value of 0. This object is read-only and is unsupported.
The CISCO-CBP-TARGET-MIB contains the following supported scalar object:
•ccbptTargetTableLastChange—Shows the value of sysUpTime at the time of the last addition or deletion of an entry in the ccbptTargetTable. If the number of entries is unchanged since the last reinitialization of the local network management system, the value of this object is 0. This object is read-only and is supported.
Notifications in the CISCO-CBP-TARGET-MIB
There are no notifications in the CISCO-CBP-TARGET-MIB.
Benefits of QoS: CBQoS Management—Policy-to-Interface Mapping Support
Simplifies QoS-to-Service-Policy Mapping
In deployments where service policies are applied to several thousand interfaces, obtaining QoS statistics and configuration information on a per interface or target basis is difficult using the organization of the CISCO-CLASS-BASED-QOS-MIB. You must perform a linear search of the cbQosServicePolicyTable within the MIB to find the corresponding cbQosPolicyIndex and then search for the configuration and statistics for the service policy applied to the interface (target).
The CISCO-CBP-TARGET-MIB offers a direct mapping from the target to the service policy applied to the target and provides the configuration information for that same service policy.
How to Configure QoS: CBQoS Management—Policy-to-Interface Mapping Support
There is no special way to configure this feature. For information on SNMP and QoS configuration tasks and examples, see the Cisco IOS Network Management Command Reference, Release 12.4T, the Cisco IOS Network Management Command Reference, and the Cisco IOS Quality of Service Solutions Command Reference, Release 12.4T, respectively.
Configuration Examples for QoS: CBQoS Management—Policy-to-Interface Mapping Support
This section provides the following configuration example:
In the following example, the configuration permits any SNMP manager to access all objects with read-only permissions using the community string public.Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.
Router(config)# snmp-server community public ro
Note There is no explicit way to configure the CISCO-CBP-TARGET-MIB. However, for information on QoS configuration tasks and examples, see the Cisco IOS Quality of Service Solutions Configuration Guide, Release 12.4.
The following sections provide references related to the QoS: CBQoS Management—Policy-to-Interface Mapping Support feature.
Related Topic Document Title
QoS commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples
Cisco IOS Quality of Service Solutions Command Reference, Release 12.4T
Cisco IOS Quality of Service Solutions Command Reference, Release 12.2 SR
QoS configuration tasks
SNMP commands: complete command syntax, command modes, command history, defaults, usage guidelines, and examples
Cisco IOS Network Management Command Reference,
Cisco IOS Network Management Command Reference,
Release 12.2 SR
SNMP configuration tasks
"Configuring SNMP Support" chapter in the Cisco IOS Network Management Configuration Guide, Release 12.4T
For information on using SNMP MIB features, see the appropriate documentation for your network management system.
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.
MIB MIBs Link
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
Management Information Base for Network Management of TCP/IP-based Internets
A Simple Network Management Protocol (SNMP)
Management Information Base for Network Management of TCP/IP-based Internets: MIB-II
This feature uses no new or modified commands.
Feature Information for QoS: CBQoS Management—Policy-to-Interface Mapping Support
Table 2 lists the release history for this feature.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 2 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
MIB—Management Information Base. A database of network management information that is used and maintained by a network management protocol such as Simple Network Management Protocol (SNMP). The value of a MIB object can be changed or retrieved by using SNMP commands, usually through a network management system. MIB objects are organized in a tree structure that includes public (standard) and private (proprietary) branches.
OID—object identifier. Values are defined in specific MIB modules.
policy map—Any defined rule that determines the use of resources within the network. A QoS policy map identifies the traffic class to which it applies and the instructions for one or more actions to take on that traffic.
QoS—quality of service. A measure of performance for a transmission system that reflects its transmission quality and service availability. Quality of service focuses on achieving appropriate network performance for networked applications; it is superior to best-effort performance.
SNMP—Simple Network Management Protocol. A management protocol used almost exclusively in TCP/IP networks. SNMP provides a means for monitoring and controlling network devices and for managing configurations, statistics collection, performance, and security.
Note See Internetworking Terms and Acronyms for terms not included in this glossary.
Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
© 2006 Cisco Systems, Inc. All rights reserved.