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This chapter describes how to configure IP to ATM Class of Service (CoS), a feature suite that maps QoS characteristics between IP and ATM.
For complete conceptual information, see the chapter "IP to ATM Class of Service Overview" in this book.
For a complete description of the IP to ATM CoS commands in this chapter, refer to the Cisco IOS Quality of Service Solutions Command Reference publication. To locate documentation of other commands that appear in this chapter, use the command reference master index, or search online.
The IP to ATM CoS feature is supported on Cisco 2600, Cisco 3600, Cisco 7200, and Cisco 7500 series routers equipped with the following hardware:
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Note Per-VC weighted fair queueing (WFQ) and class-based WFQ (CBWFQ) are not available on Cisco 7500 series routers in Cisco IOS Release 12.1. |
The IP to ATM CoS feature requires ATM PVC management and Cisco Express Forwarding (CEF) switching functionality.
See the end of this chapter for the section "Single ATM VC with WRED Group and IP Precedence Example."
| Command | Purpose |
|---|---|
random-detect-group group-name | Defines the WRED or VIP-Distributed WRED (DWRED) parameter group. |
To display the configured WRED parameters, use the following command in privileged EXEC mode:
To display the queueing statistics of an interface, use the following command in privileged EXEC mode:
| Command | Purpose |
|---|---|
show queueing interface interface-number [vc [[vpi/]vci]] | Displays the queueing statistics of a specific VC on an interface. |
To configure IP to ATM CoS on an ATM bundle, perform the tasks in the following sections. The first four sections are required; the remaining sections are optional.
The IP to ATM CoS feature requires ATM PVC management and CEF switching functionality.
See the end of this chapter for the section "VC Bundle Configuration Using a VC Class Example."
To create a bundle and enter bundle configuration mode in which you can assign attributes and parameters to the bundle and all of its member VCs, use the following command in subinterface configuration mode:
| Command | Purpose |
|---|---|
bundle bundle-name | Creates the specified bundle and enters bundle configuration mode. |
Bundle-level parameters can be applied either by assigning VC classes or by directly applying them to the bundle.
Parameters applied through a VC class assigned to the bundle are superseded by those applied at the bundle level. Bundle-level parameters are superseded by parameters applied to an individual VC.
Configuring bundle-level parameters is optional if a class is attached to the bundle to configure it.
To configure parameters that apply to the bundle and all of its members, use the following commands in bundle configuration mode:
| Command | Purpose |
|---|---|
protocol protocol {protocol-address | inarp} [[no]broadcast] | Configures a static map or enables Inverse Address Resolution Protocol (Inverse ARP) or Inverse ARP broadcasts for the bundle. |
encapsulation aal-encap | Configures the ATM adaptation layer (AAL) and encapsulation type for the bundle. |
inarp minutes | Configures the Inverse ARP time period for all VC bundle members. |
broadcast | Enables broadcast forwarding for all VC bundle members. |
oam retry up-count down-count retry frequency | Configures the VC bundle parameters related to OAM management. |
oam-bundle [manage] [frequency] | Enables end-to-end F5 OAM loopback cell generation and OAM management for all VCs in the bundle. |
Use of a VC class allows you to configure a bundle applying multiple attributes to it at once because you apply the class itself to the bundle. Use of a class allows you to generalize a parameter across all VCs, after which (for some parameters) you can modify that parameter for individual VCs. (See the section "Applying Parameters to Individual VCs" for more information.)
To configure a VC class to contain commands that configure all VC members of a bundle when the class is applied to that bundle, use the following command in vc-class configuration mode. To enter vc-class configuration mode, use the vc-class atm command.
| Command | Purpose |
|---|---|
oam-bundle [manage] [frequency] | Enables end-to-end F5 OAM loopback cell generation and OAM management for all VCs in the bundle. |
In addition to this command, you can add the following commands to a VC class to be used to configure a bundle: broadcast, encapsulation, inarp, oam retry, and protocol commands. For information on these commands, including configuration tasks and command syntax, refer to the Cisco IOS Wide-Area Networking Configuration Guide and the Cisco IOS Wide-Area Networking Command Reference.
To attach a preconfigured VC class containing bundle-level configuration commands to a bundle, use the following command in bundle configuration mode:
| Command | Purpose |
|---|---|
class-bundle vc-class-name | Configures a bundle with the bundle-level commands contained in the specified VC class. |
Parameters set through bundle-level commands contained in the VC class are applied to the bundle and all of its VC members. Bundle-level parameters applied through commands configured directly on the bundle supersede those applied through a VC class.
Note that some bundle-level parameters applied through a VC class or directly to the bundle can be superseded by commands that you directly apply to individual VCs in bundle-vc configuration mode.
To add a VC to an existing bundle and enter bundle-vc configuration mode, use the following command in bundle configuration mode:
| Command | Purpose |
|---|---|
pvc-bundle pvc-name [vpi/] [vci] | Adds the specified VC to the bundle and enters bundle-vc configuration mode in order to configure the specified VC bundle member. |
For information on how to first create the bundle and configure it, see the sections "Creating a VC Bundle" and "Applying Bundle-Level Parameters" earlier in this chapter.
Parameters can be applied to individual VCs either by using VC classes or by directly applying them to the bundle members.
Parameters applied to an individual VC supersede bundle-level parameters. Parameters applied directly to a VC take precedence over the same parameters applied within a class to the VC at the bundle-vc configuration level.
Configuring VC bundle members directly is optional if a VC class is attached to the bundle member.
To configure an individual VC bundle member directly, use the following commands in bundle-vc configuration mode:
| Command | Purpose |
|---|---|
ubr output-pcr [input-pcr] | Configures the VC for unspecified bit rate (UBR) QoS and specifies the output peak cell (PCR) rate for it. |
ubr+ output-pcr output-mcr [input-pcr] [input-mcr] | Configures the VC for UBR QoS and specifies the output PCR and output minimum guaranteed cell rate for it. |
vbr-nrt output-pcr output-scr output-mbs [input-pcr] [input-scr] [input-mbs] | Configures the VC for variable bit rate nonreal-time (VBR-nrt) QoS and specifies the output PCR, output sustainable cell rate, and output maximum burst cell size for it. |
precedence [other | range] | Configures the precedence levels for the VC. |
bump {implicit | explicit precedence-level | traffic} | Configures the bumping rules for the VC. |
protect {group | vc} | Configures the VC to belong to the protected group of the bundle or to be an individually protected VC bundle member. |
Parameters set directly for a VC at the bundle-vc configuration level take precedence over values for these parameters set for the VC at any other level, including application of a VC class at the bundle-vc configuration level.
To configure a VC class to contain commands that configure a specific VC member of a bundle when the class is applied to it, use the following commands in vc-class configuration mode. To enter vc-class configuration mode, use the vc-class atm command in global configuration mode.
| Command | Purpose |
bump {implicit | explicit precedence-level | traffic} | Specifies the bumping rules for the VC member to which the class is applied. These rules determine to which VC in the bundle traffic is directed when the carrier VC bundle member goes down. |
precedence precedence min-threshold max-threshold mark-probability-denominator | Defines precedence levels for the VC member to which the class is applied. |
protect {group | vc} | Configures the VC as a member of the protected group of the bundle or as an individually protected VC. |
You can also add the following commands to a VC class to be used to configure a VC bundle member: ubr, ubr+, and vbr-nrt.
Use of a VC class allows you to configure a VC bundle member with multiple attributes at once because you can apply the class to the VC.
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Note When a VC is a member of a VC bundle, the following commands cannot be used in vc-class mode to configure the VC: encapsulation, protocol, inarp, and broadcast. These commands are useful only at the bundle level, not the bundle member level. |
To configure the way bumping is handled for individual VCs within a bundle, use the bump command in the bundle-vc configuration mode. For more information about the bumping rules, see the section "Bumping and ATM VC Bundles" in the "IP to ATM Class of Service Overview" chapter in this book.
Configuration for an individual VC overrides the collective configuration applied to all VC bundle members through application of a VC class to the bundle.
To attach a preconfigured VC class containing bundle-level configuration commands to a bundle member, use the following command in bundle-vc configuration mode:
| Command | Purpose |
|---|---|
class-vc vc-class-name | Assigns a VC class to a VC bundle member. |
Parameters that configure a VC that are contained in a VC class assigned to that VC are superseded by parameters that are directly configured for the VC through discrete commands entered in bundle-vc configuration mode.
To configure an individual VC bundle member not to accept traffic that otherwise might be directed to it if the original VC carrying the traffic goes down, use the following command in bundle-vc configuration mode:
| Command | Purpose |
|---|---|
no bump traffic | Configures the VC not to accept any bumped traffic that would otherwise be redirected to it. |
To gather information on bundles so as to monitor them or to troubleshoot problems that pertain to their configuration or use, use one or more of the following commands in privileged EXEC mode or debug mode:
| Command | Purpose |
|---|---|
show atm bundle bundle-name | Displays the bundle attributes assigned to each bundle VC member and the current working status of the VC members. |
show atm bundle bundle-name statistics [detail] | Displays statistics or detailed statistics on the specified bundle. |
show atm map | Displays a list of all configured ATM static maps to remote hosts on an ATM network and on ATM bundle maps. |
debug atm bundle errors | Prints information on bundle errors. |
debug atm bundle events | Prints a record of bundle events. |
To configure IP to ATM CoS for per-VC WFQ and CBWFQ, perform the tasks in the following sections. The first two sections are required; the remaining sections are optional.
The IP to ATM CoS feature requires ATM PVC management and Cisco Express Forwarding (CEF) switching functionality. Per-VC WFQ and CBWFQ is supported only on Cisco 7200 series routers.
See the end of this chapter for the sections "Per-VC WFQ and CBWFQ on a Standalone VC Example" and "Per-VC WFQ and CBWFQ on Bundle-Member VCs Example."
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Note You can configure class policies for as many classes as are defined on the router, up to the maximum of 64. However, the total amount of bandwidth allocated for all classes included in a policy map to be attached to a VC must not exceed 75 percent of the available bandwidth of the VC. The remaining 25 percent of available bandwidth is used for encapsulation, such as the ATM cell overhead (also referred to as ATM cell tax), routing and best-effort traffic, and other functions that assume overhead. For more information on bandwidth allocation, see the section "CBWFQ Bandwidth Allocation" in the "Congestion Management Overview" chapter in this book. |
For information on how to configure CBWFQ and perform the tasks mentioned, see the chapter "Configuring Weighted Fair Queueing" in this book.
To attach a policy map to a standalone VC to be used as its service policy and to enable CBWFQ on that VC, use the following command in VC submode:
| Command | Purpose |
|---|---|
Router(config-if-atm-vc)#service-policy output policy-map | Enables CBWFQ and attaches the specified service policy map to the VC being created or modified. |
To attach a policy map to an individual VC bundle member to be used as its service policy and to enable CBWFQ on that VC, use the following command in bundle-vc configuration mode:
| Command | Purpose |
|---|---|
Router(config-if-atm-member)#service-policy output policy-map | Enables CBWFQ and attaches the specified service policy map to the VC being created or modified. |
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Note The service-policy output and random-detect-group commands are mutually exclusive; you cannot apply a WRED group to a VC for which you have enabled CBWFQ through application of a service policy. Moreover, before you can configure one command, you must disable the other if it is configured. |
In addition to configuring the fair-queue policy-map class configuration command, you can configure the default class with either the queue-limit command or the random-detect command, but not both. Moreover, if you want the default class to use flow-based WFQ, you cannot configure the default class with the bandwidth policy-map class configuration command--to do so would disqualify the default class as flow-based WFQ, and therefore limit application of the service policy containing the class to ABR and VBR VCs.
To create a policy map and configure the class-default class, use the following commands beginning in global configuration mode:
For more information about creating a policy map and configuring the class-default class, see the section "Class-Based Weighted Fair Queueing Configuration Task List" in the "Configuring Weighted Fair Queueing" chapter in this book.
By default--that is, even if you do not configure the class-default class with the fair-queue policy-map class configuration command and you do not configure it with the bandwidth policy-map class configuration command--the default class is defined as flow-based WFQ.
Note that you can include other classes in the same policy map as the one that contains the flow-based WFQ class. Packets not otherwise matched are selected by the default class-default class match criteria.
To attach the policy map containing the class-default class to a standalone VC so that it becomes the service policy enabling WFQ for that VC, use the following command in VC submode:
To attach the policy map containing the class-default class to an individual VC bundle member so that the policy map becomes the service policy enabling WFQ for that VC, use the following command in bundle-vc configuration mode:
To monitor per-VC WFQ and CBWFQ in your network, use one or more of the following commands in EXEC mode:
When you configure a VC in order to create or modify it, the router performs the task in interrupt mode. For this reason, the router cannot issue printf statements to inform you of error conditions, if errors occur. Rather, the router logs all error messages to the console. To accommodate these circumstances, you should enable logging of error messages to the console.
To enable logging of error messages to the console, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
logging console level | Limits messages logged to the console based on severity. |
For information on the logging console command, including configuration tasks and command syntax, refer to the Cisco IOS Configuration Fundamentals Configuration Guide and the Cisco IOS Configuration Fundamentals Command Reference.
The following sections provide IP to ATM CoS configuration examples:
For information on how to configure IP to ATM CoS, see the sections "IP to ATM CoS on a Single ATM VC Configuration Task List" and "IP to ATM CoS on an ATM Bundle Configuration Task List" in this chapter.
The following example creates a PVC on an ATM interface and applies the WRED parameter group sanjose to that PVC. Next, the IP Precedence values are configured for the WRED parameter group sanjose.
interface ATM1/1/0.46 multipoint ip address 200.126.186.2 255.255.255.0 no ip mroute-cache shutdown pvc cisco 46 encapsulation aal5nlpid random-detect attach sanjose ! random-detect-group sanjose precedence 0 200 1000 10 precedence 1 300 1000 10 precedence 2 400 1000 10 precedence 3 500 1000 10 precedence 4 600 1000 10 precedence 5 700 1000 10 precedence 6 800 1000 10 precedence 7 900 1000 10
This example configures VC bundle management on a router that uses Intermediate System-to-Intermediate System (IS-IS) as its IP routing protocol.
Bundle-Class Class
At the outset, this configuration defines a VC class called bundle-class that includes commands that set VC parameters. When the class bundle-class is applied at the bundle level, these parameters are applied to all VCs that belong to the bundle. Note that any commands applied directly to an individual VC of a bundle in bundle-vc mode take precedence over commands applied globally at the bundle level. Taking into account hierarchy precedence rules, VCs belonging to any bundle to which the class bundle-class is applied will be characterized by these parameters: aal5snap encapsulation, broadcast on, use of Inverse ARP to resolve IP addresses, and OAM enabled.
router isis net 49.0000.0000.0000.1111.00 vc-class atm bundle-class encapsulation aal5snap broadcast protocol ip inarp oam-bundle manage 3 oam 4 3 10
The following sections of the configuration define VC classes that contain commands specifying parameters that can be applied to individual VCs in a bundle by assigning the class to that VC.
Control-Class Class
When the class control-class is applied to a VC, the VC carries traffic whose IP Precedence level is 7. When the VC to which this class is assigned goes down, it takes the bundle down with it because this class makes the VC a protected one. The QoS type of a VC using this class is vbr-nrt.
vc-class atm control-class precedence 7 protect vc vbr-nrt 1000 5000 32
Premium-Class Class
When the class premium-class is applied to a VC, the VC carries traffic whose IP Precedence level is 6 and 5. The VC does not allow other traffic to be bumped onto it. When the VC to which this class is applied goes down, its bumped traffic will be redirected to a VC whose IP Precedence level is 7. This class makes a VC a member of the protected group of the bundle. When all members of a protected group go down, the bundle goes down. The QoS type of a VC using this class is vbr-nrt.
vc-class atm premium-class precedence 6-5 no bump traffic protect group bump explicitly 7 vbr-nrt 20000 10000 32
Priority-Class Class
When the class priority-class is applied to a VC, the VC is configured to carry traffic with IP Precedence in the 4-2 range. The VC uses the implicit bumping rule, it allows traffic to be bumped, and it belongs to the protected group of the bundle. The QoS type of a VC using this class is ubr+.
vc-class atm priority-class precedence 4-2 protect group ubr+ 10000 3000
Basic-Class Class
When the class basic-class is applied to a VC, the VC is configured through the precedence other command to carry traffic with IP Precedence levels not specified in the profile. The VC using this class belongs to the protected group of the bundle. The QoS type of a VC using this class is ubr.
vc-class atm basic-class precedence other protect group ubr 10000
The following sets of commands configure three bundles that the router subinterface uses to connect to three of its neighbors. These bundles are called new-york, san-francisco, and los-angeles. Bundle new-york has four VC members, bundle san-francisco has four VC members, and bundle los-angeles has three VC members.
New-York Bundle
The first part of this example specifies the IP address of the subinterface, the router protocol--the router uses IS-IS as an IP routing protocol--and it creates the first bundle called new-york and enters bundle configuration mode.
int a1/0.1 multipoint ip address 10.0.0.1 255.255.255.0 ip router isis bundle new-york
From within bundle configuration mode, the next portion of the configuration uses two protocol commands to enable IP and Open Systems Interconnect (OSI) traffic flows in the bundle. The OSI routing packets will use the highest precedence VC in the bundle. The OSI data packets, if any, will use the lowest precedence VC in the bundle. If configured, other protocols, such as IPX or AppleTalk, will always use the lowest precedence VC in the bundle.
As the indentation levels of the preceding and following commands suggest, subordinate to bundle new-york is a command that configures its protocol and a command that applies the class bundle-class to it.
protocol ip 1.1.1.2 broadcast protocol clns 49.0000.0000.2222.00 broadcast class-bundle bundle-class
The class called bundle-class, which is applied to the bundle new-york, includes a protocol ip inarp command. According to inheritance rules, protocol ip, configured at the bundle level, takes precedence over protocol ip inarp specified in the class bundle-class.
The next set of commands beginning with pvc-bundle ny-control 207, which are further subordinate, add four VCs (named ny-control, ny-premium, ny-priority, and ny-basic) to the bundle new-york. A particular class--that is, one of the classes predefined in this configuration example--is applied to each VC to configure it with parameters specified by commands included in the class.
As is the case for this configuration, to configure individual VCs belonging to a bundle, the router must be in bundle mode for the mother bundle. For each VC belonging to the bundle, the subordinate mode is pvc-mode for the specific VC.
The following commands configure the individual VCs for the bundle new-york:
pvc-bundle ny-control 207 class-vc control-class pvc-bundle ny-premium 206 class-vc premium-class pvc-bundle ny-priority 204 class-vc priority-class pvc-bundle ny-basic 201 class-vc basic-class
San-Francisco Bundle
The following set of commands create and configure a bundle called san-francisco. At the bundle configuration level, the configuration commands included in the class bundle-class are ascribed to the bundle san-francisco and to the individual VCs that belong to the bundle. Then, the pvc-bundle command is executed for each individual VC to add it to the bundle. After a VC is added and bundle-vc configuration mode is entered, a particular, preconfigured class is assigned to the VC. The configuration commands comprising that class are used to configure the VC. Rules of hierarchy apply at this point. Command parameters contained in the applied class are superseded by the same parameters applied at the bundle configuration level, which are superseded by the same parameters applied directly to a VC.
bundle san-francisco protocol clns 49.0000.0000.0000.333.00 broadcast inarp 1 class-bundle bundle-class pvc-bundle sf-control 307 class-vc control-class pvc-bundle sf-premium 306 class-vc premium-class pvc-bundle sf-priority 304 class-vc priority-class pvc-bundle sf-basic 301 class-vc basic-class
Los-Angeles Bundle
The following set of commands create and configure a bundle called los-angeles. At the bundle configuration level, the configuration commands included in the class bundle-class are ascribed to the bundle los-angeles and to the individual VCs that belong to the bundle. Then, the pvc-bundle command is executed for each individual VC to add it to the bundle. After a VC is added and bundle-vc configuration mode is entered, precedence is set for the VC and the VC is either configured as a member of a protected group (protect group) or as an individually protected VC. A particular class is then assigned to each VC to further characterize it. Rules of hierarchy apply. Parameters of commands applied directly and discretely to a VC take precedence over the same parameters applied within a class to the VC at the bundle-vc configuration level, which take precedence over the same parameters applied to the entire bundle at the bundle configuration level.
bundle los-angeles protocol ip 1.1.1.4 broadcast protocol clns 49.0000.0000.4444.00 broadcast inarp 1 class-bundle bundle-class pvc-bundle la-high 407 precedence 7-5 protect vc class-vc premium-class pvc-bundle la-mid 404 precedence 4-2 protect group class-vc priority-class pvc-bundle la-low 401 precedence other protect group class-vc basic-class
The following example creates two class maps and defines their match criteria. For the first map class, called class1, the numbered access control list (ACL) 101 is used as the match criterion. For the second map class, called class2, the numbered ACL 102 is used as the match criterion.
Next, the example includes these classes in a policy map called policy1. For class1, the policy includes a minimum bandwidth allocation request of 500 Mbps and maximum packet count limit of 30 for the queue reserved for the class. For class2, the policy specifies only the minimum bandwidth allocation request of 1000 Mbps, so the default queue limit of 64 packets is assumed. Note that the sum of the bandwidth requests for the two classes comprising policy1 is 75 percent of the total amount of bandwidth (2000 Mbps) for PVC cisco to which the policy map is attached.
The example attaches the policy map called policy1 to the PVC called cisco. Once the policy map policy1 is attached to PVC cisco, its classes constitute the CBWFQ service policy for that PVC. Packets sent on this PVC will be checked for matching criteria against ACLs 101 and 102 and classified accordingly.
Because class-default is not explicitly configured for this policy map, all traffic that does not meet the match criteria of the two classes comprising the service policy is handled by the predefined class-default class, which provides best-effort flow-based WFQ.
class-map class1 match access-group 101 class-map class2 match access-group 102 policy-map policy1 class class1 bandwidth 500 queue-limit 30 class class2 bandwidth 1000 interface ATM1/1/0.46 multipoint ip address 200.126.186.2 255.255.255.0 pvc cisco 46 vbr-nrt 2000 2000 encap aal5snap service policy output policy1
The following example shows a PVC bundle called san-francisco with members for which per-VC WFQ and CBWFQ are enabled and service policies configured. The example assumes that the classes included in the following policy maps have been defined and that the policy maps have been created: policy1, policy2, and policy4. For each PVC, the IP to ATM CoS pvc-bundle command is used to specify the PVC to which the specified policy map is to be attached.
Note that PVC 0/34 and 0/31 have the same policy map attached to them, policy2. Although you can assign the same policy map to multiple VCs, each VC can have only one policy map attached at an output PVC.
bundle san-francisco protocol ip 1.0.2.20 broadcast encapsulation aal5snap pvc-bundle 0/35 service policy output policy1 vbr-nrt 5000 3000 500 precedence 4-7 pvc-bundle 0/34 service policy output policy2 vbr-nrt 5000 3000 500 precedence 2-3 pvc-bundle 0/33 vbr-nrt 4000 3000 500 precedence 2-3 service policy output policy4 pvc-bundle 0/31 service policy output policy2
Posted: Mon Aug 21 21:30:27 PDT 2000
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