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Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 16 Fragmenting and Interleaving Real-Time and Nonreal-Time Packets
FRF.12 Fragmentation
FRF.12 Fragmentation Inheritance
Table 16-4
describes FRF.12 Fragmentation inheritance when you configure LFI on a Frame Relay
interface, subinterface, or DLCI (either directly or using a map class with LFI enabled).
FRF.12 Fragmentation and Hierarchical Policies
To configure FRF.12 Fragmentation, you must first configure a hierarchical service policy and attach it
to a Frame Relay interface, subinterface, or data-link connection identifier (DLCI) in one of the
following ways:
•
Directly using the
service-policy
command
•
Using a Frame Relay map class
Fragmentation is enabled only when a hierarchical service policy is attached. The hierarchical service
policy you define must identify and allocate queues for real-time (priority) traffic and nonreal-time
traffic.
Example 16-8
creates a serial T1 interface and defines a service policy for both real-time and
nonreal-time traffic. You can create the T1 interface under any higher level channelized interface that
supports T1 tributaries or the T1/E1 line card interface. In the example, the child policy map named
policy_12_p0 defines QoS actions for three traffic classes: prec_q0 for priority traffic, prec_q1 for
non-priority traffic, and prec_q2 for non-priority traffic. The parent policy map named policy_13 shapes
traffic for all of the traffic classes to 256 kbps. The
service-policy
command is used to apply the child
policy to the parent policy. When applying the service policy to an interface, subinterface, or DLCI, use
the
service-policy
command and specify the
output
keyword for FRF.12 Fragmentation.
Example 16-8 Defining a Hierarchical Service Policy
Router(config)#
t1 1 channel-group 1 timeslot 1-24 speed 56
!
Router(config)#
class-map match-all prec_q2
Router(config-cmap)#
match ip precedence 2
Router(config-cmap)#
class-map match-all prec_q0
Router(config-cmap)#
match ip precedence 0
Router(config-cmap)#
class-map match-all prec_q1
Router(config-cmap)#
match ip precedence 1
!
Router(config)#
policy-map policy_12_p0
Router(config-pmap)#
class prec_q0
Router(config-pmap-c)#
priority
Router(config-pmap-c)#
police 64000
Router(config-pmap-c)#
class prec_q1
Router(config-pmap-c)#
bandwidth percent 39
Router(config-pmap-c)#
class prec_q2
Router(config-pmap-c)#
bandwidth percent 4
!
Router(config)#
policy-map policy_13
PVC-Based Frame Relay LFI Inheritance
LFI Enabled
Traffic Subject to LFI
Interface
All PVCs on the interface and its subinterfaces
Subinterface
All PVCs on the subinterface
DLCI
DLCI only