Guest

Cisco IOS Software Releases 12.0 S

8-Port OC-3 STM-1 ATM Line Card for Cisco 12000 Series Internet Routers

  • Viewing Options

  • PDF (403.4 KB)
  • Feedback
8-Port OC-3 STM-1 ATM Line Card for Cisco 12000 Series Internet Routers

Table Of Contents

8-Port OC-3 STM-1 ATM Line Card for Cisco 12000 Series Internet Routers

Feature Overview

Benefits

Restrictions

Related Features and Technologies

Related Documents

Supported Platforms

Supported Standards, MIBs, and RFCs

Configuration Tasks

Selecting an 8-Port OC-3 STM-1 ATM Line Card Interface

Configuring Virtual Circuits

Configuring Permanent Virtual Circuits

Using PVC Configuration Commands

Back-to-Back 8-Port OC-3 STM-1 ATM Line Card Connection

Configuring Interfaces

Default or Initial Interface Configuration

Configuring the Interface

Verifying Operation

Configuration Examples

Configuring Per-VC Queue Limits

Configuring Per-VC WRED

Configuring Per-VC MDRR and Low Latency Queueing

Configuring Per-VC MDRR and Low Latency Queueing with Queue Limits

Configuring Per-VC MDRR and Low Latency Queueing with RED and WRED

Verifying the Configuration

Command Reference

atm pvp

queue-limit

random-detect precedence

service-policy

show controller atm

ubr

debug lc atm cos

debug lc atm sar


8-Port OC-3 STM-1 ATM Line Card for Cisco 12000 Series Internet Routers


Feature History

Release
Modification

12.0(22)S

This feature was introduced on Cisco 12000 series Internet Routers.

12.0(23)S

Software support for the 8-Port OC-3 STM-1 ATM line card was expanded to include ATM Cell Loss Priority (CLP) bit setting, ATM virtual circuit (VC) bundle management, MPLS virtual private network (VPN) Carrier supporting Carrier (CsC), MPLS VPN Inter-Autonomous Systems (Inter-AS), and 128-line input Access Control Lists (ACLs).


This feature module describes the Cisco 8-Port OC-3 STM-1 ATM line card and its use in the Cisco 12000 series Internet Routers.

This document includes information on the following sections:

Feature Overview

Supported Platforms

Supported Standards, MIBs, and RFCs

Configuration Tasks

Configuration Examples

Command Reference

Feature Overview

The 8-Port OC-3 STM-1 ATM line card supports traffic shaping and delivers line rate OC-3/STM-1 bandwidth while performing traffic shaping and per-virtual circuit (VC) queueing. It also supports per-VC Modified Deficit Round Robin (MDRR) with per-VC low latency queueing (LLQ).

MDRR is implemented on a per-VC basis, with up to eight queues per VC. One of the queues is a low latency queue (LLQ). Both per-VC Weighted Random Early Detection (WRED) and per-VC MDRR are performed in hardware.

The 8-Port OC-3 STM-1 ATM line card provides the Cisco 12000 series product line with eight 155 Mbps ATM interfaces. The card communicates with the Cisco 12000 series product line switch fabric.

Benefits

Traffic shaping on a per-VC and per-virtual path (VP) basis with N x 64kbps shaping granularity.

Per-VC queueing using configurable per-VC queue limits or per-VC WRED.

Supports up to 2048 traffic-shaped VC connections per interface.1

Alternatively supports up to 1024 MDRR VC connections per interface with per-VC LLQ capability.1

Bidirectional OC-3 line rate for 64-byte packets (2 cells) on all eight ports. This is an aggregate line rate of approximately 2.8 million packets per second.

A VC address can be any of the virtual path identifier (VPI) (0..255) and virtual channel identifier (VCI) (0..65535) range.

Per-VC statistics through hardware.

Per-port statistics through hardware.

AAL5 [I.362] [I.363] reassembly and segmentation.

VBR-nRT traffic shaping with 99+ percent shaping accuracy.

Unspecified bit rate (UBR) with support for optional peak cell rate (PCR) parameter with 99+ percent shaping accuracy.

VP tunnel traffic shaping for up to 250 VP tunnels per port.

Maximum transmission unit (MTU) of up to 9180 bytes.

Support for 2048 simultaneous reassemblies per port with an average of 1024 bytes per reassembly.

F4 and F5 flows of operation, administration and maintenance (OAM) cells and OAM management specified as requirements by [UNI 3.x] [I.610].

Basic Multiprotocol Label Switching (MPLS) forwarding.

MPLS virtual private network (VPN).

UNI 3.x and Interim Local Management Interface (ILMI).

Switched virtual circuit (SVC) support for point-to-point and point-to-multipoint connections.

Multicast packet replication.

Supports up to 56 distinct WRED profiles per interface. These profiles are configurable using Cisco IOS software.

Support for ATM CLP bit setting.

Support for ATM VC bundle management.

Support for 128-line input ACLs.

Support for MPLS VPN Inter-AS.

Support for MPLS VPN CsC.

Restrictions

The following qualifications apply when you are configuring an 8-Port OC-3 STM-1 ATM line card:

You can configure VCs using any VPI/VCI values on up to 256 VPIs per port. However, if you configure more than 256 VCs per port using sparse VCI numbers, this may restrict the configuration to fewer than the maximum of 2048 VCs per port. It is recommended that you use contiguous VCI numbers inside each VPI.

If you configure eight traffic classes, one class must be explicitly configured as the priority class.

You can configure either per-VC queue limits or random-detect, but not both on the same queue.

Related Features and Technologies

Multiprotocol Label Switching (MPLS)

Layer 3 quality-of-service (QoS)

Weighted Random Early Detection (WRED)

Modified Deficient Round Robin (MDRR)

Low Latency Queueing (LLQ)

See the "Related Documents" in the next section for a list of documents that describe these features and technologies.

Related Documents

The following documents provide additional information about installing and configuring the 8-Port OC-3 STM-1 ATM line card:

8-Port OC-3 STM-1 ATM Line Card Installation and Configuration

Release Notes for Cisco 12000 Series Routers for Cisco IOS Release 12.0 S

Release Notes for Cisco IOS Release 12.0 S

Cisco IOS Release 12.0 Wide-Area Networking Configuration Guide

Weighted Random Early Detection on the Cisco 12000 Series Router

Multiprotocol Label Switching on Cisco Routers

MPLS Virtual Private Networks

Modular Quality of Service Command-Line Interface

For information on the software features added in the 12.0(23)S release, see the Release Notes for Cisco 12000 Series Routers for Cisco IOS Release 12.0 S. The MPLS VPN Inter-AS and CsC features are described in the release notes. The remaining three software features added in 12.0(23)S have separate feature module publications that provide additional information about these features:

ATM Cell Loss Priority Setting on Cisco 12000 Series 8-Port OC-3 STM-1 ATM Line Cards

ATM VC Bundle Management on Cisco 12000 Series 8-Port OC-3 STM-1 ATM Line Cards

128-Line Input Access Control Lists on Cisco 12000 Series 8-Port OC-3 STM-1 ATM Line Cards

You can also find additional information in the installation and configuration guide for your Cisco 12000 series Internet Router and in the Cisco IOS Release 12.0 documentation set.

Supported Platforms

The 8-Port OC-3 STM-1 ATM line card is compatible with all Cisco 12000 series Internet Routers and Cisco 12400 series Internet Routers that are operating with Cisco IOS Release 12.0(22)S or later.

Supported Standards, MIBs, and RFCs

Standards

AAL5 [I.362] [I.363] reassembly and segmentation

F4 and F5 flows of OAM cells and OAM management specified as requirements by [UNI 3.X][I.610]

Multiprotocol Encapsulation [RFC1483] with support for LLC/SNAP encapsulation and VC multiplexing, and NLPID encapsulation

Classical IP and ARP over ATM; Client and ARP Server [RFC1577][RFC1755][RFC1626]

Interim Local Management Interface (ILMI) [UNI 3.X]

Default IP MTU for use over ATM AAL5 [RFC1626]

ATM Signaling Support for IP over ATM [RFC1755]

VBR-NRT

UBR

MIBs

In addition to industry-standard Simple Network Management Protocol (SNMP) and other Management Information Bases (MIBs) supported on the Cisco 12000 series Internet Router, the 8-Port OC-3 STM-1 ATM line card also supports the following:

ATM-MIB

CISCO-AAL5-MIB

CISCO-ATM-EXT-MIB

IF-MIB

SONET-MIB

CISCO-IETF-ATM2-PVCTRAP-MIB

MPLS-TE-MIB

CISCO-QUEUE-MIB

To obtain lists of supported MIBs by platform and Cisco IOS software release, and to download MIB modules, go to the Cisco MIB website on Cisco.com at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.

Configuration Tasks

See the following sections for configuration tasks for the 8-Port OC-3 STM-1 ATM line card.

Selecting an 8-Port OC-3 STM-1 ATM Line Card Interface

Configuring Virtual Circuits

Configuring Interfaces

Verifying Operation

Selecting an 8-Port OC-3 STM-1 ATM Line Card Interface

The interface of the 8-Port OC-3 STM-1 ATM line card interface is referred to as "atm" in the configuration commands. An interface is created for each 8-Port OC-3 STM-1 ATM line card found in the system at reset time.

To select a specific 8-Port OC-3 STM-1 ATM line card interface, use the interface atm slot/port.subifnum command:

Router(config)# interface atm slot/port.subifnum

Configuring Virtual Circuits

A virtual circuit (VC) is a point-to-point connection between two ATM devices. A virtual circuit is established for each ATM end node with which the router communicates. The characteristics of the virtual circuit are established when the virtual circuit is created and include the following for the 8-Port OC-3 STM-1 ATM line card:

Quality of service (QoS)

ATM adaptation layer (AAL) mode (AAL5 only)

Encapsulation type (LLC/SNAP, IP MUX, and NLPID)

Peak and average transmission rates

Configuring Permanent Virtual Circuits

Each permanent virtual circuit (PVC) configured on the router remains active until the circuit is removed from the configuration. All virtual circuit characteristics apply to PVCs. When a PVC is configured, all configuration options are passed to the 8-Port OC-3 STM-1 ATM line card. These PVCs are written to the nonvolatile RAM (NVRAM) as part of the configuration and are used when the Cisco IOS image is reloaded.

Using PVC Configuration Commands

When you create a PVC, you create a virtual circuit descriptor (VCD) and attach it to the VPI and VCI. The VCD tells the card which VPI/VCI to use for a particular packet. The 8-Port OC-3 STM-1 ATM line card requires this feature to manage the packets for transmission. The number chosen for the VCD is independent of the VPI/VCI used.

When you create a PVC, you also specify the AAL and encapsulation. To create a PVC on an 8-Port OC-3 STM-1 ATM line card interface, use the atm pvc command:

Router(config-subif)# pvc vpi/vci
Router(config-if-atm-vc)#

where

vpi is the ATM network VPI to use for this virtual circuit, in the range of 0 to 255.

vci is the ATM network VCI to use for this virtual circuit, in the range of 0 to 65,535.

To configure the VBR-NRT QoS and specify output peak cell rate, output sustainable cell rate, and output maximum burst cell size for an ATM PVC, SVC, or VC class, use the following command:

Router(config-if-atm-vc)# vbr-nrt peak average [burst]

where

peak is the maximum rate, in kbps, at which this virtual circuit can transmit data. This is a layer 2 rate in kbps of IP, ATM, and AAL5 overhead. It does not include layer 1 SONET overhead.

average is the average rate, in kbps, at which this virtual circuit transmits data. This is a layer 2 rate in kbps of IP, ATM, and AAL5 overhead. It does not include layer 1 SONET overhead.

burst is a value between 1 and 8192 that specifies the maximum number of ATM cells the virtual circuit can transmit to a network at the peak rate of the PVC. Other router platforms multiply the number by a factor to get the actual number of burst cells. On this platform, the factor is 1 (the burst is configured in units of 1 cell).

To configure a nondefault QoS on the PVC, use the following command:

Router(config-if-atm-vc)# ubr peak

To change the type of encapsulation, use the following command:

Router(config-if-atm-vc)# encapsulation {aal5mux | aal5mlpid | aal5snap}

To remove a PVC, use the no form of this command:

Router(config-subif)# no pvc vpi/vci

The following is an example of the atm pvc command:

Router(config)# interface atm 2/0.1 point-to-point
Router(config-subif)# pvc 1/128
Router(config-if-atm)# vbr-nrt 100 100 256

The pvc command creates PVC n and attaches the PVC to VPI and VCI.


Note The atm pvc command is supported, but not recommended.


Back-to-Back 8-Port OC-3 STM-1 ATM Line Card Connection

The following is an example of the configuration of two routers, each containing an 8-Port OC-3 STM-1 ATM line card connected directly back-to-back with a standard cable. This arrangement allows you to verify the operation of the ATM port and to link the routers directly in order to build a larger node. To connect two routers, attach the cable to the ATM port on each one.

By default, the 8-Port OC-3 STM-1 ATM line card expects a connected ATM switch to provide transmit clocking.

The configuration of the first router is as follows:

interface ATM3/0
atm clock internal
interface atm 3/0.1 point-to-point
ip address 1.0.0.1 255.0.0.0
pvc 1/5
!

The configuration of the second router is as follows:

interface ATM3/0.1 point-to-point
ip address 1.0.0.2 255.0.0.0
pvc 1/5
!

Configuring Interfaces

Use the show running-config command to display current port configuration information. On power up, the interface on a new 8-Port OC-3 STM-1 ATM line card is shut down. To enable the interface, you must enter a no shutdown command in configuration mode.

Default or Initial Interface Configuration

When the 8-Port OC-3 STM-1 ATM line card is enabled (taken out of shutdown) with no additional configuration commands applied, the default interface configuration file parameters, described in Table 1, are used.

Table 1 8-Port OC-3 STM-1 ATM Line Card Default Configuration Values

Parameter
Configuration File Entry
Default Value

Maximum transmission unit (MTU)

[no] mtu bytes

4470 bytes

Maximum numbers of virtual circuits

[no] atm maxvc numvc

2048

Cisco Discovery Protocol (CDP)

[no] cdp enable

Enabled

Loopback

[no] loopback [diagnostic | line]

Loopback line

Internal clock

[no] atm clock internal

no atm clock internal

SONET framing

[no] atm sonet stm-1

no atm sonet stm-1


To enter a no shutdown command for an interface on a 8-Port OC-3 STM-1 ATM line card or to change the configuration of an interface, you must enter configuration mode by using the configure privileged EXEC command.

Configuring the Interface

After you verify that the new 8-Port OC-3 STM-1 ATM line card is installed correctly, use the configure command to configure the new interface. Be prepared with the information that you will need, such as the interface IP address.

Use the following procedure to create a basic configuration, including enabling an interface and specifying IP routing. You might also need to enter other configuration subcommands, depending on the requirements for your system configuration.

(For descriptions of configuration subcommands and the configuration options available, see the appropriate software publications in the "Related Documents" section.)

The Cisco 12000 series Internet Router identifies an interface address by its line card slot number and port number, in the format slot/port. Because each 8-Port OC-3 STM-1 ATM line card contains eight ATM interfaces, the port numbers are 0 to 7. For example, the slot/port address of an ATM interface on an 8-Port OC-3 STM-1 ATM line card installed in line card slot 2 is 2/0 to 2/7.

Before you can use the configure command, you must enter the privileged level of the EXEC command interpreter using the enable command. The system will prompt you for a password if one is set.

To configure an interface on the 8-Port OC-3 STM-1 ATM line card, perform the following steps:

 
Command
Purpose

Step 1 

Router# show version

Confirm that the system recognizes the line card.

Step 2 

Router# show interfaces

Check the status of each port on the line card.

Step 3 

Router# configure terminal

Enter configuration mode and specify that the console terminal will be the source of the configuration subcommands.

Step 4 

Router(config)# interface atm slot/port.subifnum {point-to-point | multipoint}

Specify the new ATM subinterface to configure. For example, to configure port three, subinterface 2 of an 8-Port OC-3 STM-1 ATM line card in interface processor slot 1, enter:

Router(config)# interface atm 1/3.2 multipoint

Step 5 

Router(config-subif)# ip address 10.1.2.3 255.255.255.255

Assign an IP address and subnet mask to the interface.

Step 6 

Router(config-subif)# pvc vpi/vci

Configure a PVC. For example to configure the PVC using VPI 1 and VCI 17, enter:

Router(config-if)# pvc 1/17


Note For traffic to flow successfully, PVCs must use the same VPI and VCI numbers on both sides of the line.


Step 7 

Router(config-if-atm-vc)# interface atm slot/port

Change to the ATM interface. For example, to configure port 3 of an 8-Port OC-3 STM-1 ATM line card in interface processor slot 1, enter:

Router(config)# interface atm 1/3

Step 8 

Router(config-if)# no shutdown

Change the shutdown state to up and enable the interface.

Step 9 

(Use any other configuration subcommands required to enable routing protocols and adjust the interface characteristics.)

Complete the configuration based on the unique and specific requirements of your network.

Step 10 

Press Ctrl-Z to exit configuration mode.

Exit configuration mode.

Step 11 

Router# copy running-config startup-config

Write the new configuration to memory.

Verifying Operation

To verify the operation of the interfaces configured on the 8-Port OC-3 STM-1 ATM line card, perform the following steps:

 
Command
Purpose

Step 1 

Router# show version

Displays the configuration of the system hardware, the software release, the names and sources of configuration files, and the boot images. Verify that the list includes the newly configured 8-Port OC-3 STM-1 ATM line card ports and interfaces.

Step 2 

Router# show gsr

Displays information about the hardware modules installed in the Cisco 12000 series Internet Router.

Step 3 

Router# show interfaces atm slot/port

Displays information about the ATM interfaces. For example, to display information about slot 2, port 0, enter:

Router# show interfaces atm 2/0

Step 4 

Router# show running-config

Displays information about the currently running configuration in RAM.

To display information about the current state of the ATM network and the connected virtual circuits, follow these steps:

 
Command
Purpose

Step 1 

Router# show atm interface atm slot/port

Displays current ATM-specification information about the 8-Port OC-3 STM-1 ATM line card interface.

Step 2 

Router# show atm traffic

Displays current ATM statistics.

Step 3 

Router# show atm pvc

Displays current ATM PVC information.

Step 4 

Router# show atm vc

Displays current ATM VC information.

Configuration Examples

This section provides configuration examples.

Configuring Per-VC Queue Limits

In the following example, per-VC queue limits are configured on a single queue.

First, configure the policy map:

Router(config)# policy-map qlimit1
Router(config-pmap)# class class-default
Router(config-pmap-c)# queue-limit 576 cells
Router(config-pmap-c)# exit
Router(config-pmap)# exit

Then, attach the policy map to an ATM subinterface.

Router(config)# int atm4/0.1 point-to-point
Router(config-subif)# pvc 4/11
Router(config-if-atm-vc)# service-policy output qlimit1

Configuring Per-VC WRED

In the following example, simple WRED is configured on a VC without MDRR.

In this example, class-default is a special class. It is the only kind of class that can be configured without using the bandwidth or priority commands.

Router(config)# policy-map WRED-1
Router(config-pmap)# class class-default ! <- must use class-default for
Router(config-pmap)#                  ! per-VC WRED without per-VC MDRR
Router(config-pmap-c)# random-detect
Router(config-pmap-c)# random-detect exponential-weighting-constant 10
Router(config-pmap-c)# random-detect precedence 0 300 cells 700 cells 1
Router(config-pmap-c)# random-detect precedence 1 350 cells 800 cells 1
Router(config-pmap-c)# random-detect precedence 2 400 cells 900 cells 1
Router(config-pmap-c)# random-detect precedence 3 450 cells 1000 cells 1
Router(config-pmap-c)# random-detect precedence 4 500 cells 1100 cells 1
Router(config-pmap-c)# random-detect precedence 5 550 cells 1200 cells 1
Router(config-pmap-c)# random-detect precedence 6 600 cells 1300 cells 1
Router(config-pmap-c)# random-detect precedence 7 650 cells 1400 cells 1

Once the policy map has been created, configure it on the VC using the service-policy command:

Router(config-if)# exit
Router(config)# int atm1/0.1
Router(config-if)# pvc 1/1
Router(config-if-atm-vc)# service-policy output WRED-1

Configuring Per-VC MDRR and Low Latency Queueing

Using MDRR, the 8-Port OC-3 STM-1 ATM line card supports up to eight queues for classes of traffic per VC. One of the queues is always reserved for a special class called class-default. Up to seven of the classes are normal queues, including the class-default queue. The eighth class is always a low latency queue.

The class, class-default, is always configured, and it consumes one of the eight queues. If not configured explicitly, it is configured implicitly. When the bandwidth command is used, at least 1 percent of traffic must be reserved for the class-default queue. The class-default queue receives all IP/MPLS precedences that are not configured in another class on the same policy.

The low latency queue is also always created. All traffic sourced from the router (including ping traffic and multicast traffic) uses this queue, regardless of precedence.

Bandwidth percentages are converted into weights in units of ATM cells. The weights are internally proportioned such that the bandwidth is divided accurately between VCs.

The following are recommendations for configuring per-VC MDRR on the 8-Port OC-3 STM-1 ATM line card:

Set bandwidth percentages in increments of 10 percent or greater (for example, 10%, 11%, 12%, and so on, not 1%, 2%, 3%,...9%). Ensure that the bandwidth percentages for nondefault classes add up to no more than 90 percent.

Set the MTU as low as possible on each subinterface, using the ip mtu command, while still avoiding fragmentation. Fragmentation causes extreme performance degradation, because it is done in the slow path. Do not decrease the MTU to the point where it causes fragmentation.


Note Changing MTU settings may cause all VCs on the interface or subinterface to be torn down and set back up.


In the following example, precedence 6-7 traffic is given strict priority over all other traffic (which may cause starvation). To give precedence 4-5 traffic 50 percent of the remaining bandwidth and precedence 0-3 traffic the remaining 50 percent, follow the steps below.

First, configure three class-maps, as follows:

Router(config)# class-map match-any MDRR-CLASS-GOLD
Router(config-cmap)# match ip precedence 6 7
Router(config-cmap)# match mpls experimental 6 7

Router(config)# class-map match-any MDRR-CLASS-SILVER
Router(config-cmap)# match ip precedence 4 5
Router(config-cmap)# match mpls experimental 4 5

Router(config)# class-map match-any MDRR-CLASS-BRONZE
Router(config-cmap)# match ip precedence 0 1 2 3
Router(config-cmap)# match mpls experimental 0 1 2 3

You can also configure this example using two class-maps and then use the class-default to include all other traffic. It is also possible to configure more than 4 precedences in a single class; however, it requires the use of additional match commands.

Next, attach all three classes to a policy map. If none of the classes is a priority class, the maximum number of classes configurable, including the class-default class, is seven. When class-default is not specified, at least 1 percent must be allocated to this class.

Router(config)# policy-map MDRR-POLICY-1
Router(config-pmap)# class MDRR-CLASS-GOLD
Router(config-pmap-c)# priority
Router(config-pmap-c)# class MDRR-CLASS-SILVER
Router(config-pmap-c)# bandwidth remaining percent 50
Router(config-pmap-c)# class class-default

The class named class-default is attached, instead of MDRR-CLASS-BRONZE, to avoid having an extra class. This is the recommended way to configure a policy map for the 8-Port OC-3 STM-1 ATM line card.


Note If specific values for WRED thresholds and queue limits are not required on the default queue, it is not necessary for you to configure the class-default. A default queue is always created for traffic classes that have not been included in the classes specified in the policy map.


If priority is not specified on class MDRR-CLASS-GOLD, or if bandwidth percent is specified on MDRR-CLASS-GOLD instead of priority, then bandwidth percent must be used instead of bandwidth remaining percent on the other classes.

After the policy map has been created, configure it on the VC using the service-policy command.

Router(config)# int atm1/0
Router(config-if)# int atm1/0.1 point-to-point
Router(config-if)# ip address 106.1.1.1 255.255.255.0
Router(config-if)# ip mtu 1500
Router(config-if)# pvc 1/1
Router(config-if-atm)# service-policy output MDRR-POLICY-1
Router(config-if-atm)# end

Configuring Per-VC MDRR and Low Latency Queueing with Queue Limits

In the following example, per-VC MDRR and LLQ are configured with nondefault queue limits.

First, configure three class-maps, as follows:

Router(config)# class-map match-any MDRR-CLASS-GOLD
Router(config-cmap)# match ip precedence 6 7
Router(config-cmap)# match mpls experimental 6 7

Router(config)# class-map match-any MDRR-CLASS-SILVER
Router(config-cmap)# match ip precedence 4 5
Router(config-cmap)# match mpls experimental 4 5

Router(config)# class-map match-any MDRR-CLASS-BRONZE
Router(config-cmap)# match ip precedence 0 1 2 3
Router(config-cmap)# match mpls experimental 0 1 2 3

Next, configure the policy map:

Router(config)# policy-map MDRRandQlimit
Router(config-pmap)# class MDRR-CLASS-GOLD
Router(config-pmap-c)# priority
Router(config-pmap-c)# class MDRR-CLASS-SILVER
Router(config-pmap-c)# bandwidth remaining percent 50
Router(config-pmap-c)# queue-limit 576 cells
Router(config-pmap-c)# class class-default
Router(config-pmap-c)# queue-limit 576 cells

After the policy map has been created, configure it on the VC using the service-policy command. You must configure an IP address on the interface or subinterface to which the VC is attached in order for the service policy to take effect.

Router(config)# int atm1/0.1 point-to-point
Router(config-subif)# ip address 106.1.1.1 255.255.255.0
Router(config-subif)# ip mtu 1500
Router(config-subif)# pvc 1/1
Router(config-if-atm-vc)# service-policy output MDRR-POLICY-1
Router(config-if-atm-vc)# end

Configuring Per-VC MDRR and Low Latency Queueing with RED and WRED

This example configures WRED and MDRR in the same policy map. WRED has different behavior when combined with MDRR, because the queue depths for WRED are calculated per class/queue.


Note Random-detect cannot be configured on a class that has priority configured.


First, configure three class-maps, as follows:

Router(config)# class-map match-any COS-CLASS-GOLD
Router(config-cmap)# match ip precedence 6 7
Router(config-cmap)# match mpls experimental 6 7

Router(config)# class-map match-any COS-CLASS-SILVER
Router(config-cmap)# match ip precedence 4 5
Router(config-cmap)# match mpls experimental 4 5

Router(config)# class-map match-any COS-CLASS-BRONZE
Router(config-cmap)# match ip precedence 0 1 2 3
Router(config-cmap)# match mpls experimental 0 1 2 3

Attach the class map for all three classes to a policy map. If none of the classes is a priority class, the maximum number of classes configurable, including the class-default class, is seven.

Router(config)# policy-map WRED-MDRR-POLICY-1
Router(config-pmap)# class COS-CLASS-GOLD
Router(config-pmap-c)# priority

Router(config-pmap-c)# class COS-CLASS-SILVER
Router(config-pmap-c)# bandwidth remaining percent 50
Router(config-pmap-c)# random-detect
Router(config-pmap-c)# random-detect exponential-weighting-constant 10
Router(config-pmap-c)# random-detect precedence 4 500 cells 1100 cells 1
Router(config-pmap-c)# random-detect precedence 5 550 cells 1200 cells 1

Router(config-pmap-c)# class class-default
Router(config-pmap-c)# random-detect
Router(config-pmap-c)# random-detect exponential-weighting-constant 10
Router(config-pmap-c)# random-detect precedence 0 300 cells 700 cells 1
Router(config-pmap-c)# random-detect precedence 1 350 cells 800 cells 1
Router(config-pmap-c)# random-detect precedence 2 400 cells 900 cells 1
Router(config-pmap-c)# random-detect precedence 3 450 cells 1000 cells 1

After the policy map has been created, configure it on the VC using the service-policy command.

Router(config)# int atm1/0.1 point-to-point
Router(config-subif)# ip address 106.1.1.1 255.255.255.0
Router(config-subif)# ip mtu 1500
Router(config-subif)# pvc 1/1
Router(config-if-atm-vc)# service-policy output WRED-MDRR-POLICY-1

Verifying the Configuration

To verify that the policy map is configured correctly, use the show policy-map command.

Router# show policy-map int atm4/0.4
 ATM4/0.4: VC 1/70 -

   Service-policy output: WRED-MDRR-POLICY-1 (1189)

    Class-map: COS-CLASS-GOLD (match-any) (1190/13)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: ip precedence 6   7   (1192)
        0 packets, 0 bytes
        5 minute rate 0 bps
      Match: mpls experimental   6   7   (1194)
        0 packets, 0 bytes
        5 minute rate 0 bps
Class of service queue: 2
Tx Queue (PRIORITY configured)
Class-map: COS-CLASS-SILVER (match-any) (1196/14)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: ip precedence 4   5   (1198)
        0 packets, 0 bytes
        5 minute rate 0 bps
      Match: mpls experimental   4   5   (1200)
        0 packets, 0 bytes
        5 minute rate 0 bps
Class of service queue: 1
Tx Queue (DRR configured)
bandwidth percent               Weight
        50                      94
Tx Random-detect:
Exp-weight-constant: 10 (1/1024 )
Precedence       RED Label      min             max             Mark
4               4               500             1100            1
5               5               550             1200            1

    Class-map: class-default (match-any) (1203/0)
      0 packets, 0 bytes
      5 minute offered rate 0 bps, drop rate 0 bps
      Match: any   (1205)
        0 packets, 0 bytes
        5 minute rate 0 bps
Class of service queue: 0
Tx Queue (DRR configured)
bandwidth percent               Weight
        0                       94
Tx Random-detect:
Exp-weight-constant: 10 (1/1024 )
Precedence       RED Label      min             max             Mark
0               0               300             700             1
1               1               350             800             1
2               2               400             900             1
3               3               450             1000            1

Command Reference

This section documents new and modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command reference publications.

atm pvp

queue-limit

random-detect precedence

service-policy

show controller atm

ubr

Use the following debug commands to help troubleshoot the 8-Port OC-3 STM-1 ATM line card:

debug lc atm cos

debug lc atm sar

atm pvp

To create a permanent virtual path (PVP) used to multiplex (or bundle) one or more VCs into a VP tunnel, use the atm pvp interface configuration command. To remove a permanent virtual path, use the no form of this command.

atm pvp vpi [peak-rate [sustained-rate max-burst-size]]

no atm pvp vpi

Syntax Description

vpi

ATM network virtual path identifier (VPI) of the VC to multiplex on the permanent virtual path. The range is 0 to 255. The VPI is an 8-bit field in the header of the ATM cell. The VPI value is unique only on a single link, not throughout the ATM network, because it has local significance only. The VPI value must match that of the switch.

peak-rate

(Optional) Maximum rate in kbps at which the PVP can transmit data. The range is 84 kbps to line rate. The default is the line rate.

sustained-rate

(Optional) Average rate in kbps at which the PVP can transmit data. The range is 84 kbps to peak rate.

max-burst-size

(Optional) Maximum burst size in number of cells. The range is 1 to 8192. The default is 94.


Defaults

PVP is not configured.

Command Modes

Interface configuration, but not subinterface configuration

Command History

Release
Modification

11.1

This command was introduced.

12.0(22)S

The optional sustained-rate and max-burst-rate arguments were added to this command to support the 8-Port OC-3 STM-1 ATM line card on the Cisco 12000 series Internet Routers.


Usage Guidelines

All subsequently created VCs with a vpi matching the vpi specified with the atm pvp command are multiplexed onto this PVP. This PVP connection is an ATM connection where switching is performed on the VPI field of the cell only. A PVP is created and left up indefinitely. All VCs that are multiplexed over a PVP share and are controlled by the traffic parameters associated with the PVP.

When you create a PVP, two VCs are created (VCI 3 and 4) by default. These VCs are created for VP end-to-end loopback and segment loopback OAM support.

If the number specified for the VPI is already used by an existing VC, the command is rejected. If the number specified for this VPI is already used by a PVP, the existing PVP traffic parameter values are replaced with the newly specified values.

Hierarchical shaping is not supported on the 8-Port OC-3 STM-1 ATM line card. If a VPI is configured using the atm pvp command, you cannot specify UBR or VBR traffic shaping on VCs with the same VPI. For example, if you configure atm pvp 47, VCIs that have a VPI of 47 do not support per-VC traffic shaping.

To verify the configuration of a PVP, use the show atm vp command.

Examples

The following example creates a permanent virtual path (VP tunnel) with a peak rate of 140000 Kbps, sustained rate of 100000 Kbps, and maximum burst size of 1 cell, along with 2 PVCs that belong to it. Traffic on the 2 PVCs will be shaped according to the parameters configured for the VP tunnel.

interface atm 6/0
 atm PVP 1 140000 100000 1
interface atm 6/0.1 point-to-point
ip addr 106.1.1.1 255.255.255.0
pvc 1/101
   encap aal5snap
interface atm 6/0.2 point-to-point
ip addr 107.1.1.1 255.255.255.0
   pvc 1/102
   encap aal5snap
end

Related Commands

Command
Description

show atm vp

Displays the statistics for all VPs on an interface or for a specific VP.


queue-limit

To specify or modify the maximum number of ATM cells a queue can hold, use the queue-limit policy map class configuration command. To remove the queue limit from a class, use the no form of this command.

queue-limit number-of-cells cells

no queue-limit number-of-cells cells

Syntax Description

number-of-cells

Threshold in the range from 1 to 65535 specifying the maximum number of ATM cells that the queue for this class can accumulate. When the queue length reaches the threshold, all packets coming in to the queue are dropped until the queue length is lower than the threshold.

cells

For the 8-Port OC-3 STM-1 ATM line card on the Cisco 12000 series Internet Router, the queue limit threshold must be specified as a count of ATM cells.


Defaults

On the 8-Port OC-3 STM-1 ATM line card for the Cisco 12000 router, the default value is 192 cells (two default MTU-sized packets). See Table 1 for the values of the default MTU.

If per-VC MDRR is configured, the default queue limit is proportional to bandwidth and MTU.

On most other platforms, the default is 64 packets.


Note To control latency on your per-VC queue, use the following rule of thumb:
latency = queue limit/shape rate.


Command Modes

policy map class configuration

Command History

Release
Modification

12.0(5)T

This command was introduced.

12.0(5)XE

This command was integrated into Cisco IOS Release 12.0(5)XE. Support for VIP-enabled Cisco 7500 series routers was added.

12.1(5)T

This command was integrated into Cisco IOS Release 12.1(5)T. Support for VIP-enabled Cisco 7500 series routers was added.

12.0(22)S

The cells keyword was added to this command to specify the queue threshold value as a count of ATM cells, as required to support the 8-Port OC-3 STM-1 ATM line card for the Cisco 12000 series Internet Routers.


Usage Guidelines

A queue is created for every class for that uses the bandwidth or priority commands. A queue is always created for the class-default class. Packets satisfying the match criteria for a class accumulate in the queue reserved for the class until they are sent, which occurs when the queue is serviced by the MDRR process. When the queue limit you defined for the class is reached, enqueueing of any further packets to the queue causes tail drop to take effect.

Examples

The following example configures a policy map called qlimit576 to contain policy for class-default. Policy for this class is set so that the queue reserved for it has a maximum packet limit of 576 cells.

policy-map qlimit576
 class class-default
  queue-limit 576 cells

Related Commands

Command
Description

bandwidth

Sets a bandwidth value for an interface.

class class-name

Specifies the name of the class whose policy you want to create or change, and the default class (commonly known as the class-default class) before you configure its policy.

class class-default

Specifies the default traffic class whose bandwidth is to be configured or modified.

policy-map policy-name

Creates or modifies a policy map that can be attached to one or more interfaces to specify a service policy.

priority

Gives priority to a class within a policy map.

random-detect

Enables WRED.


random-detect precedence

To configure Weighted Random Early Detection (WRED) parameters for a particular IP precedence, use the random-detect precedence policy map class configuration command. To return the values to the default for the precedence, use the no form of this command.

random-detect precedence precedence min-threshold cells max-threshold cells [mark-prob-denominator]

no random-detect precedence precedence min-threshold cells max-threshold cells [mark-prob-denominator]

Syntax Description

precedence

IP precedence number. The value range is 0 to 7.

min-threshold

Minimum threshold in number of cells. The value range of this argument is 1 to 65535. When the average queue length reaches the minimum threshold, WRED drops all packets with the specified IP precedence.

max-threshold

Maximum threshold in number of cells. The value range of this argument is 1 to 65535. When the average queue length exceeds the maximum threshold, WRED drops all packets with the specified IP precedence.

cells

On the 8-Port OC-3 STM-1 ATM line card for the Cisco 12000 series Internet Router, the min-threshold and max-threshold values must be specified as a count of ATM cells.

mark-prob-denominator

Denominator for the fraction of packets dropped when the average queue depth is at the maximum threshold. For example, if the denominator is 512, one out of every 512 packets is dropped when the average queue is at the maximum threshold. The value range is 1 to 32768. The default is 8; one out of every eight packets is dropped at the maximum threshold.


Note For the 8-Port OC-3 STM-1 ATM line card, the mark probability denominator is rounded to the nearest power of 2.



Defaults

For all precedences, the default mark-prob-denominator is 8, and the default max-threshold for the 8-Port OC-3 STM-1 ATM line card is 576 cells.

The default min-threshold depends on the precedence. The min-threshold for IP precedence 0 corresponds to half of the max-threshold. The values for the remaining precedences fall between half the max-threshold and the max-threshold at evenly spaced intervals. The max-threshold value must be larger than the min-threshold value; it cannot be less than or equal to it. The min-threshold and max-threshold values should differ by a power of two.

Table 2 lists the default minimum threshold value for each IP precedence.

Table 2 Default WRED Minimum Threshold Values 

 
Minimum Threshold Value
(Fraction of Maximum Threshold Value)
IP Precedence
WRED

0

288 cells

1

324 cells

2

360 cells

3

396 cells

4

432 cells

5

468 cells

6

504 cells

7

540 cells


Before you can use the random-detect precedence command, you must first use the random-detect command to enable WRED.

Command Modes

policy map class configuration

Command History

Release
Modification

11.1 CC

This command was introduced.

12.0(22)S

This command was modified to support the 8-Port OC-3 STM-1 ATM line card. The keyword cells was added to distinguish between different units of measurement (packets vs. ATM cells) for the minimum and maximum thresholds. The 8-Port OC-3 STM-1 ATM line card requires that thresholds be configured in cells.


Usage Guidelines

When you apply a service policy containing the random-detect command to a VC on an 8-Port OC-3 STM-1 ATM line card, packets are given preferential treatment based on the IP precedence of the packet. Use the random-detect precedence command to adjust the treatment for different IP precedences.

If you want WRED to ignore the precedence when determining which packets to drop, enter this command with the same parameters for each precedence. Remember to use reasonable values for the minimum and maximum thresholds.


Note The default WRED parameter values are based on the best available data. We recommend that you do not change the parameters from their default values unless you have determined that your applications would benefit from the changed values. At most, 56 unique WRED profiles can be configured per interface. (A WRED profile is the combination of min-threshold, max-threshold, mark-prob-denominator, and exponential-weighting-constant.)


The WRED feature is supported on these Cisco router platforms:

Cisco 1600 series

Cisco 2500 series

Cisco 3600 series

Cisco 4000 series (including 4500 and 4700 series)

Cisco 7200 series

Cisco 7500 series with RSP interface card

Cisco 12000 series

Examples

The following example enables WRED on the interface and specifies parameters for the different IP precedences:

router(config)# policy-map wred1
router(config-pmap)# class class-default
router(config-pmap-c)# random-detect
router(config-pmap-c)# random-detect precedence 0 288 cells 576 cells 1
router(config-pmap-c)# random-detect precedence 1 324 cells 576 cells 1
router(config-pmap-c)# random-detect precedence 2 360 cells 576 cells 1
router(config-pmap-c)# random-detect precedence 3 396 cells 576 cells 1
router(config-pmap-c)# random-detect precedence 4 432 cells 576 cells 1
router(config-pmap-c)# random-detect precedence 5 468 cells 576 cells 1
router(config-pmap-c)# random-detect precedence 6 504 cells 576 cells 1
router(config-pmap-c)# random-detect precedence 7 540 cells 576 cells 1
router(config-pmap-c)# random-detect exponential-weighting-constant 9
router(config)# interface ATM4/7.1 point-to-point
router(config-subif)# ip address 4.7.1.1 255.255.255.0
router(config-subif)# ip mtu 1500
router(config-subif)# pvc 47/11 
router(config-if-atm-vc)# service-policy out wred1

Related Commands

Command
Description

random-detect

Enables WRED.

random-detect exponential-weighting-constant

Configures the WRED exponential weight factor for the average queue size calculation.


service-policy

To attach a policy map to an output virtual circuit (VC), to be used as the service policy for that VC, use the service-policy interface configuration command. To remove a service policy from an output VC, use the no form of this command.

service-policy output policy-map-name

no service-policy output policy-map-name

Syntax Description

output

Attaches the specified policy map to the output VC.

policy-map-name

The name of a service policy map (created using the policy-map command) to be attached.


Defaults

No service policy is specified.

Command Modes

VC submode

Command History

Release
Modification

12.0(5)T

This command was introduced.

12.0(5)XE

This command was integrated into Cisco IOS Release 12.0(5)XE.

12.0(7)S

This command was integrated into Cisco IOS Release 12.0(7)S.

12.1(1)E

This command was integrated into Cisco IOS Release 12.1(1)E.

12.1(2)T

This command was integrated into Cisco IOS Release 12.l(2)T. This command was modified to enable low latency queueing (LLQ) on Frame Relay VCs.

12.0(22)S

This command was integrated into Cisco IOS Release 12.0(22)S to support the 8-Port OC-3 STM-1 ATM line card for the Cisco 12000 series Internet Routers.


Usage Guidelines

You can attach a service policy to one or more VCs on the 8-Port OC-3 STM-1 ATM line card to specify the policy map for those VCs. A VC can have, at most, one service policy attached.

The service-policy command is used to attach a policy map (and the associated policies) to a VC. The command is only applicable to packets going out on the VC.

Examples

The following example shows how to attach the service policy map called WRED-1 to the VC on interface ATM 1/0.1:

int atm1/0.1 point-to-point
  pvc 1/1
     service-policy output WRED-1

Related Commands

Command
Description

class-map

Creates a class map for the specified class.

policy-map

Creates or modifies a policy map that can be attached to one or more interfaces to specify a service policy.

show policy-map

Displays the configuration of all classes for a specified service policy map or all classes for all existing policy maps.

show policy-map interface

Displays the configuration of all classes configured for the service policy on the specific PVC on the point-to-point subinterface.


show controller atm

To display the ATM-specific configuration on the line card, use the line card show controller atm privileged EXEC command.

show controller atm port# {vcconfig [vcid#] | traffic [vcid#]}

Syntax Description

port#

The physical port on the 8-Port OC-3 STM-1 ATM line card (0-7).

vcconfig

Displays information about the VC configuration.

traffic

Displays statistics for a VC.

vcid

Specifies a particular VC.


Command Modes

Privileged EXEC

Command History

Release
Modification

12.0(22)S

This command was introduced.


Examples

The following is sample output from the show controller atm vcconfig command:


Router#exec slot 1 show controller atm 0 vcconfig

========= Line Card (Slot 4) =======

Active VPs: 0, VCs: 4


VCID VPI  VCI ChID Type    PCR    SCR  MBS  OutInfo MacString
   1  10   10 0104 VBR    2000   1000  256 10001910 0103014000000000AAAA030000000800 
                                           00000000  
   3  10   12 0099 VBR    1000    500   94 10001918 0099014000000100AAAA030000000800 
                                           00000000  
   8  10   17 00A3 UBR       0      0   94 10001921 00A3014000000000AAAA030000000800 
                                           00000000  
   4  10   13 010F VBR    5000   2500   94 10001948 010D014000000200AAAA030000000800 
                                           00000000 

The following is sample output from the show controller atm vcconfig command where the vcid is specified:

Router#exec slot 1 show controller atm 0 vcconfig 1

========= Line Card (Slot 1) =======


VCID VPI  VCI ChID Type    PCR    SCR  MBS  OutInfo MacString
   1   1    1 010F VBR    5000   2500   94 10001948 010D014000000200AAAA030000000800 
              010D                         10001948 010D014000000200AAAA030000000800 
              010D                         10001949 010D014000000300AAAA030000000800 
              010D                         1000194A 010D014000000400AAAA030000000800 
              010D                         1000194B 010D014000000500AAAA030000000800 
              010E                         1000194C 010E014000000600AAAA030000000800 
              010E                         1000194D 010E014000000700AAAA030000000800 
              010F                         1000194E 010F014000000000AAAA030000000800 
              010F                         1000194F 010F014000000000AAAA030000000800 
                                           00000000  
              010D                         00000000  
              010D                         00000000  
              010D                         00000000  
              010D                         00000000  
              010E                         00000000  
              010E                         00000000  
              010F                         00000000  
              010F                         00000000  

The following is sample output from the show controller atm traffic command:

Router#exec slot 1 show controller atm 0 traffic

========= Line Card (Slot 1) =======


VCID     InPkts        InBytes   PktsInSW   InOams    OutPkts       OutBytes
   1          0              0          0        0          0              0
   3    2221086      239503824    2214417     6669     939262      101440296
   8          0              0          0        0          0              0
   4          0              0          0        0          0              0

SAR Counters:
  tx_packets            :             939262  tx_bytes             :          101440296
  tx_total_resource_errs:            1275155  tx_total_other_errs  :                  0
  tx_wred_thresh_drops  :                  0  tx_wred_random_drops :            1275155
  rx_packets            :            2221086  rx_bytes             :          239503824
  rx_total_resource_errs:                  0  rx_total_other_errs  :              17475
  rx_buffer_exhaust_errs:                  0  rx_CRC32_errors      :                  0
  rx_packet_abort_errs  :                  0  rx_trailer_len_errs  :              12138
  rx_mps_errors         :                  0  rx_reassembly_timeout:                  0
The following are per-SAR counters:
  sys_rx_unopen_vc_cls  :                132  sys_tx_unopen_vc_cls :                  0
  sys_ecc_errors        :                  0  sys_ecc_and_addr     :         0xFFFFFFFF
  sys_ecc_or_addr       :         0x00000000

The following is sample output from the show controller atm traffic command where the vcid is specified:

Router#exec slot 1 slot controller atm 0 traffic 1

========= Line Card (Slot 1) =======


VCID: 1, VPI: 1, VCI: 1

Rx Total Stats:
 rx_packets     :                  0  rx_bytes      :                  0
 rx_resource_err:                  0  rx_other_err  :                  0
 rx_sw_packets  :                  0  rx_oam_cells  :                  0

Tx Stats:
 COSQ #0 (ChID=010D)
 tx_packets     :                  0  tx_bytes      :                  0
 tx_resource_err:                  0  tx_other_err  :                  0
 tx_queue_depth :                  0  tx_avg_q_depth:             0.0000

 COSQ #1 (ChID=010E)
 tx_packets     :                  0  tx_bytes      :                  0
 tx_resource_err:                  0  tx_other_err  :                  0
 tx_queue_depth :                  0  tx_avg_q_depth:             0.0000

 COSQ #7 (ChID=010F)
 tx_packets     :                  0  tx_bytes      :                  0
 tx_resource_err:                  0  tx_other_err  :                  0
 tx_queue_depth :                  0  tx_avg_q_depth:             0.0000

Tx Total Stats:
 tx_packets     :                  0  tx_bytes      :                  0
 tx_resource_err:                  0  tx_other_err  :                  0

Table 3 describes per-interface counters displayed by the show controller atm command.

Table 3 show controller atm Per-Interface Counters 

Counter
Description

tx_packets

A 64-bit counter of the number of packets transmitted on this interface, including OAM cells. This should be approximately equal to the sum of the number of packets on all the VCs on this interface. (If traffic stops for a few seconds, these numbers should be exactly equal.)

tx_bytes

A 64-bit counter of the bytes transmitted on this interface, including OAM cells and AAL5 header encapsulations (such as AAL5SNAP). This should be approximately equal to the sum of the bytes transmitted on each of the VCs.

tx_total_resource_errs

The total number of packets that were not transmitted due to any resource exhaustion error. This does not necessarily imply an error, because this counter includes tx_wred_thresh_drops and tx_wred_random_drops, as well as packet drops due to complete buffer exhaustion on the SAR. This should be approximately equal to the sum of the number of resource errors that occur on all the VCs.


Note Buffer exhaustion should not occur if you have not oversubscribed the queue thresholds on the interface.


tx_total_other_errs

The total number of packets that were not transmitted due to any error other than resource exhaustion, but not including "no-vc" drops. This includes malformed packets, CRC errors, and so on. This should be approximately equal to the sum of the number of tx_other_errors that occur on all the VCs on this interface.

tx_wred_thresh_drops

The total number of WRED maximum threshold drops on this interface. This counter is not available as a per-VC counter. This counter is included in the tx_total_resource_errs counter.

tx_wred_random_drops

The total number of WRED random drops on this interface. This counter is not available as a per-VC counter. This counter is included in the tx_total_resource_errs counter.

rx_packets

The total number of packets reassembled on this interface by the SAR, including OAM cells.

rx_bytes

The total number of bytes reassembled on this interface by the SAR, including AAL5 encapsulation bytes.

rx_total_resource_errs

The total number of packet reassemblies that failed due to resource exhaustion. This error should not occur if the queue thresholds are not oversubscribed. This error includes rx_buffer_exhaust_errs.

rx_total_other_errs

The total number of packet reassemblIes that failed due to errors besides resource exhaustion (not including "no-vc" cells), including rx_crc32_errors, rx_packet_abort_errs, rx_trailer_len_errs, rx_mps_errors, and rx_reassembly_timeout.

rx_buffer_exhast_errs

The total number of packet reassemblies that failed due to complete buffer exhaustion on the SAR. This error should not occur if the queue thresholds are not oversubscribed. This is included in rx_total_resource_errs.

rx_crc32_errors

The number of packet reassemblies that failed due to an invalid AAL5 CRC32 trailer. This is included in rx_total_other_errs.

rx_packet_abort_errs

The number of packet reassemblies that failed due to receiving a trailer length of 0. This is included in rx_total_other_errs.

rx_trailer_len_errs

The number of packet reassemblies that failed due to a packet whose AAL5 trailer had an invalid trailer length. This is included in rx_total_other_errs.

rx_mps_errors

The number of packet reassemblies that failed due to a packet size greater than the maximum allowed packet size. This is included in rx_total_other_errs.

rx_reassembly_timeout

The number of packet reassemblies that failed due to timing out before receiving the last cell of a packet. This is included in rx_total_other_errs.


ubr

To select Unspecified Bit Rate (UBR) QOS and configure the output peak cell rate for an ATM PVC, SVC, or VC class, use the ubr command in the appropriate command mode. Use the no form of this command to remove the UBR parameter.

ubr pcr

no ubr pcr

Syntax Description

pcr

The output peak cell rate in kilobits per second (includes layer 2 ATM and AAL5 overhead, but does not include layer 1 SONET overhead).


Defaults

UBR QOS at the maximum line rate of the physical interface.

Command Modes

Interface-ATM-VC configuration (for an ATM PVC or SVC)

VC-class configuration (for a VC class)

Command History

Release
Modification

11.3

This command was introduced.

12.0(13)S

This command was modified to support the 4-Port OC-3 STM-1 ATM line card for the Cisco 12000 series Internet Routers. Because the 4-Port OC-3 STM-1 ATM line card did not support the pcr parameter, that parameter was removed from this command for only the Cisco 12000 series Internet Routers.

12.0(22)S

This command was modified to support the 8-Port OC-3 STM-1 ATM line card for the Cisco 12000 series Internet Routers. The 8-Port OC-3 STM-1 ATM line card supports the output peak cell rate functionality. Because the 8-Port OC-3 STM-1 ATM line card does not support the optional input-pcr parameter for SVCs, that parameter does not appear in this command.


Usage Guidelines

Configure QOS parameters using the ubr or vbr-nrt command. The last command you enter will apply to the PVC or SVC you are configuring.

If the ubr command is not explicitly configured on an ATM PVC or SVC, the VC inherits the following default configuration (listed in order of next highest precedence):

Configuration of any QOS command (ubr or vbr-nrt) in a VC class assigned to the PVC or SVC itself.

Configuration of any QOS command (ubr or vbr-nrt) in a VC class assigned to the PVC's or SVC's ATM subinterface.

Configuration of any QOS command (ubr or vbr-nrt) in a VC class assigned to the PVC's or SVC's ATM main interface.

Global default: UBR QOS at the maximum line rate of the PVC or SVC.

Examples

The following example specifies the pcr for an ATM PVC to be 100,000 Kbps:

pvc 1/32
 ubr 100000

The following example specifies the pcr for an ATM SVC to be 10,000 Kbps:

svc lion nsap 47.0091.81.000000.0040.0B0A.2501.ABC1.3333.3333.05
 ubr 10000

Related Commands

Command
Description

pvc

Creates a PVC.

vbr-nrt

Configures the VBR-NRT QoS and specifies output peak cell rate, output sustainable cell rate, and output maximum burst cell size for an ATM PVC, SVC, or VC class.


debug lc atm cos

Use the debug lc atm cos EXEC command to display information about a VC that is using per-VC ATM class of service (COS) features. The no form of this command disables debugging output.

[no] debug lc atm cos

Command History

Release
Modification

12.0(22)S

This command was introduced to support the8-Port OC-3 STM-1 ATM line card.


Usage Guidelines

This command displays information about the setup, teardown, and modification of a VC with per-VC WRED, per-VC MDRR, or per-VC queue limits (a PVC with a service policy attached). Use the debug lc atm cos command to verify mapping of precedences to per-VC MDRR queues, mapping of precedences to WRED packs, and mapping of policy maps and MDRR weights to queues. The output of this command depends on the configuration of the VC(s).

Examples

The following is sample output from the debug lc atm cos command:

Router# exec slot 1 debug lc atm cos

SLOT 4:1d19h: cos_queue_group command received: slot=4, port=7, vcid=2
SLOT 4:1d19h: no wred configured.
SLOT 4:1d19h: mdrr configured.
SLOT 4:1d19h: prec=0, red_label=7, queue=1
SLOT 4:1d19h: prec=1, red_label=7, queue=2
SLOT 4:1d19h: prec=2, red_label=7, queue=3
SLOT 4:1d19h: prec=3, red_label=7, queue=4
SLOT 4:1d19h: prec=4, red_label=7, queue=5
SLOT 4:1d19h: prec=5, red_label=7, queue=6
SLOT 4:1d19h: prec=6, red_label=7, queue=0
SLOT 4:1d19h: prec=7, red_label=7, queue=0
SLOT 4:1d19h: prec_all_config = 0, prec_all_red_label = 7
SLOT 4:1d19h: red_label=0, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: red_label=1, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: red_label=2, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: red_label=3, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: red_label=4, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: red_label=5, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: red_label=6, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: red_label=7, min=-1, max=-1, drop=65535, weight=1
SLOT 4:1d19h: queue=0, weight=122, qlimit=262144, no priority
SLOT 4:1d19h: queue=1, weight=113, qlimit=262144, no priority
SLOT 4:1d19h: queue=2, weight=216, qlimit=262144, no priority
SLOT 4:1d19h: queue=3, weight=103, qlimit=262144, no priority
SLOT 4:1d19h: queue=4, weight=150, qlimit=262144, no priority
SLOT 4:1d19h: queue=5, weight=94, qlimit=262144, no priority
SLOT 4:1d19h: queue=6, weight=141, qlimit=262144, no priority
SLOT 4:1d19h: queue=7, weight=0, qlimit=262144, strict priority

This is the output for a VC that has per-VC MDRR, per-VC WRED, or queue limits configured. Each line begins with a slot number and timestamp.

The first line indicates that some form of COS is configured on the VC (either MDRR, WRED, or queue limits). The next two lines show that MDRR is configured, but WRED is not. Because WRED is not configured, this VC is using the default of queue limits with default values.

The next eight lines provide information about which queue number and RED label are matched to each precedence. This tells you which queue will receive traffic for a given precedence and what RED label will be applied to traffic for that precedence.

The next eight lines give more information about each RED label (values of -1 mean that this RED label is not used). The line that contains prec_all_config should be ignored.

The last eight lines describe the weights, queue limits, and priority of each queue. The weight is the number of consecutive ATM cells that are transmitted from a given queue before transmitting any cells from the other queues on this VC.

The qlimit is the maximum number of ATM cells that are allowed to queue up before tail-dropping packets destined to this queue. If this value is 262144, it is ignored and the default queue limit is applied to this queue. Also, if WRED is applied to this queue, the queue limit will be ignored. Notice that queue 7 has a weight of 0. This is because this is the priority or low latency queue. It is always allowed to empty its queue whenever it gets a turn.

debug lc atm sar

Use the debug lc atm sar EXEC command if you are experiencing problems with your line card.. The no form of this command disables debugging output.

[no] debug lc atm sar

Command History

Release
Modification

12.0(22)S

This command was introduced to support the8-Port OC-3 STM-1 ATM line card.


Usage Guidelines

Under normal conditions, this does not give any output. If you experience problems with your line card, turn this debug on and provide any output to your technical support representative. To use this command, you must use the execute-on command, as follows:

exec slot 1 debug lc atm sar

1 Subject to overall system configuration.