Mobile Wireless Home Agent Feature for IOS

This chapter discusses concepts related to Quality of Service on the Cisco Mobile Wireless Home Agent,
and provides details about how to configure this feature.
This chapter includes the following sections:

• Overview of HA QoS, page 13-1
• Configuring HA QoS, page 13-3
• QoS Configuration Examples, page 13-3
Overview of HA QoS
Currently, the Home Agent does not support the ability to limit traffic based on rate specified on a
per-user basis for various user-subscribed services such as Voice over IP (VoIP), Push-to-Talk (PTT) etc.
The per-binding flow policing feature provides the ability to forward packets at rates enforced by a
NAI-based user and appropriate for each binding registered on the Home Agent.
Note Per-binding flow means one binding per NAI.
The key benefits of this feature include the following:
• Utilizes the robust Modular QoS CLI (MQC) for performing QoS actions.
• Ensures the original DSCP options are preserved in the downstream packets originated from the
internet to the MN, by copying the DSCP from the inner to the outer tunnel header.
• Identifies, classifies, and polices traffic for individual or all users in a realm registered on the Home
Agent. This is done for upstream and downstream traffic. The use of MQC allows operators to group
user traffic according to a classmap and policymap, and dynamically specify bandwidth
requirements at the time of binding flow identification.
13-2

QoS Policing
On the Cisco HA, QoS policing is enabled as follows:
Step 1 A user attaches a service-policy to an APN virtual interface recognized by the QoS infrastructure. This
is done using the extended ip mobile realm command for convenience of performing policing for a
group of NAI-based users (on a per-realm basis). This allows a user-configured policymap to be applied
to the APN interface, which helps to classify Mobile IP data packets through the HA. Also the peak-rate
can be specified to MQC in either input (downstream) or output (upstream) directions.
Step 2 Using MQC classmap/policymap commands, a “match flow pdp” filter is configured that classifies
packets for individual flows (bindings) and informs the HA to send police parameters during flow
identification. Police rate pdp peak-rate pdp commands, along with the burst values and the various
actions needed, are configured under the policy-map, for the class-map for which the match type is flow
pdp. Peak-rate values for the upstream and downstream are configured using the ip mobile realm
command.
After the initial RRQ processing, when a binding is registered on the Home Agent, the first packet
corresponding to a binding is intercepted in CEF path and policing rules are applied to it. Based on this
behavior, police action is invoked on subsequent packets according to configured peak rate, conform
burst, and exceed burst values. MQC QoS determines when a user police request has exceeded the
configured rate and accordingly permits or drops the packet. For every active binding, a QoS flow exists
and a run time state is stored on the HA.
Restrictions
Please note following restrictions:
• Only single-rate policing is allowed. There is no bandwidth reservation, so policing is done based
on a maximum bandwidth rate specified by user.
• Once the service policy attachment and police actions are configured they cannot be modified. To
modify policy or associated parameters, the existing service policy needs to be removed and a new
one configured in its place.
• Policing can be applied only to users registering using a NAI username.
• In the MQC command set when match flow pdp is configured for a class only the police command
can be configured. Other actions are not allowed.
• There is no traffic shaping feature implemented.
13-3

Configuring HA QoS
To enable the HA QoS feature, perform the following tasks:
The above configuration details have the following restrictions:
• You cannot remove one of the policies (either input or output) if both policies are configured.
• You cannot modify the existing service-policy for a realm without unconfiguring and then
configuring it.
• You cannot configure output-policy first, and then input policy.\

 
QoS Configuration Examples
Here is a configuration example for the QoS feature on the Cisco Mobile Wireless HA:
class-map match-all class-mip
match flow pdp
policy-map policy-mip-flow
class class-mip
police rate pdp burst 1400 peak-rate pdp peak-burst 1700
conform-action transmit
exceed-action drop
violate-action drop
ip mobile realm @cisco.com service-policy input policy-mip-flow peak-rate 9000 output
policy-mip-flow peak-rate 8000
Command Purpose
Step 1 Router(config)ip mobile realm [nai | realm]
[service-policy {input policy-name [peak-rate rate]
|output policy-name [peak-rate rate]}]
Configures a policy and associated rate for one or
more user bindings belonging to that policy on the
basis of NAI/realm. This can be configured for both
upstream and downstream traffic.
Step 2 Router(conf t)# class-map class-name Specifies a class map name and enters global
classmap mode.
Step 3 Router(config-cmap)#match flow pdp Classifies HA packets for each binding belonging to
a class of MN users with a specified rate.
Step 4 Router(config-pmap-c)# police rate pdp [burst bytes]
[peak-rate pdp [peak-burst bytes]] conform-action
action [exceed-action action [violate-action
action]]
Invokes a specified police action on a binding flow.
peak-rate pdp keywords ensure that policing is done
based on the rate specified for each binding flow.
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Cisco Mobile Wireless Home Agent Feature for IOS 12.4(15)XM
Chapter 13 Home Agent Quality of Service
Overview of HA QoS
Verifying the Configuration
To dislay various statistics for the HA QoS feature, perform the following tasks:
 
Show Command Examples
The following examples display QoS binding statistics and aggregate statistics:
Router#sh ip mob bind police nai mip-qos-user1@cisco.com:
Mobility Binding List:
Total number of QoS bindings is 1
mip-qos-user1@cisco.com:
Downlink Policing
police:
rate 8000 , bc 1400 bytes
peak-rate 9000, be 1700 bytes
conformed 3000 packets, 312000 bytes; actions:
drop
exceeded 0 packets, 0 bytes; actions:
drop
violated 0 packets, 0 bytes; actions:
drop
Uplink Policing
police:
rate 8000 , bc 1400 bytes
peak-rate 8000, be 1700 bytes
conformed 6000 packets, 516000 bytes; actions:
drop
exceeded 0 packets, 0 bytes; actions:
drop
violated 0 packets, 0 bytes; actions:
drop
Router#
Router#sh policy-map apn realm cisco.com
APN 566497294
Service-policy input: toMN
Class-map: HA4.0 (match-all)
1 packets, 118 bytes
30 second offered rate 0 bps, drop rate 0 bps
Match: flow pdp
police:
rate pdp, bc 1400 bytes
peak-rate pdp, be 1700 bytes
conformed 0 packets, 0 bytes; actions:
transmit
exceeded 0 packets, 0 bytes; actions:
Command Purpose
Step 1 Router#show ip mobile binding police nai
@example.com
Displays when QoS policing is enabled, statistics for
each individual binding, and is provided as an
extension to the existing show ip mobile binding
command. Details such as police rate in bps, and the
packets that have conformed, exceeded, or violated
the rate are displayed.
Step 2 Router# show policy-map apn realm string Displays aggregate statistics on a per-realm basis.
13-5

drop
violated 0 packets, 0 bytes; actions:
drop
Class-map: class-default (match-any)
0 packets, 0 bytes
30 second offered rate 0 bps, drop rate 0 bps
Match: any
Service-policy output: fromMN
Class-map: HA4.0 (match-all)
1 packets, 100 bytes
30 second offered rate 0 bps, drop rate 0 bps
Match: flow pdp
police:
rate pdp, bc 1400 bytes
peak-rate pdp, be 1700 bytes
conformed 1 packets, 100 bytes; actions:
transmit
exceeded 0 packets, 0 bytes; actions:
drop
violated 0 packets, 0 bytes; actions:
drop
Class-map: class-default (match-any)
0 packets, 0 bytes
30 second offered rate 0 bps, drop rate 0 bps
Match: any
Router#
13-6