Cisco 10000 Series User Manual

11-16
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 11 Managing Packet Queue Congestion
Controlling Congestion Using Weighted Random Early Detection
On the PRE3, the number of WRED profiles supported per policy map depends on the number of
interfaces with attached service policies:
• When less than 32,000 interfaces have service policies, the PRE3 supports 21 non-default WRED
profiles and 16 default profiles per policy map. The 16 default profiles includes profiles for the
class-default queue, net-control, and two priority queues. However, you cannot configure the default
profiles for net-control and priority queues. Therefore, the PRE3 allows default profiles for 12
non-default (user) queues and one class-default queue per policy map.
• When 32,000 to 64,000 interfaces have service policies, the PRE3 supports any combination of
non-default WRED and default profiles. The maximum total number of profiles (non-default and
default) supported in a policy map is 21.
• When less than 32,000 interfaces have service policies, the PRE3 supports up to 21 non-default
WRED profiles and up to 16 default profiles per policy map. The 16 default profiles include the
class-default, net-control, and two priority queues. However, the default profiles for net-control and
priority queues are not user-configurable; therefore the actual number of default profiles for
user-configured queues is 12 with one class-default class per policy map.
Table 11-6 summarizes the WRED profiles supported by various PREs.
random-detect atm-clp clp-value
min-thresh-value max-thresh-value
mark-probability-denominator-value
PRE3 and PRE4
random-detect atm-clp clp-value
min-thresh-value max-thresh-value
mark-probability-denominator-value
A number that indicates the drop eligibility of a
packet based on the ATM CLP. Valid values are 0
or 1.
random-detect cos cos-value min-thres-value
max-thresh-value
mark-probability-denominator
PRE3 and PRE4
random-detect cos cos-value min-thres-value
max-thresh-value
mark-probability-denominator
A number that indicates the drop eligibility of a
packed based on the CoS bit. Valid values are
from 0 to 7.
Table 11-5 WRED Drop Profile Commands
Command Description
Ta b l e 11-6 WRED Profiles Support
Performance
Routing Engine
Number of Non-
Default WRED Profiles
Number of Default Profiles
Per Policy Map
Number Interfaces with
Service Policies
PRE1 4 No hard limit Va r ie s
1
1. Depends on a combination of factors, such as the number of queues on the router and packet heaps. Changes in the queue
length and the number of classes per policy map also affect the number of interfaces on which policy maps can be applied.
PRE2 8 No hard limit Va ri e s
2
PRE3 21 per policy map 16
3
per policy map Less than 32,000
21 total explicit and default profiles per policy map 32,000 to 64,000

Cisco 10000 Series Specifications

General

Brand	Cisco
Model	10000 Series
Category	Network Router
Language	English