44-15
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 44 Configuring Quality of Service
Configuring VSS QoS
Note The classification action “match qos-group” is not supported in Cisco Release IOS XE 3.4.0SG and IOS
15.1(2)SG.
Note The QoS feature “set qos-group” is not supported in Cisco Release IOS XE 3.4.0SG and IOS 15.1(2)SG.
Platform Hardware Capabilities
Prerequisites for Applying a QoS Service Policy
Unlike the Switch QoS model, there is no prerequisite for enabling QoS on various targets. Just the
attachment of a service policy enables QoS and detachment of that policy disables QoS on that target.
Restrictions for Applying a QoS Service Policy
Traffic marking can be configured on an interface, a VLAN, or a port and VLAN. An interface can be a
Layer 2 access port, a Layer 2 switch trunk, a Layer 3 routed port, or an EtherChannel. A policy is
attached to a VLAN using vlan configuration mode.
Attaching QoS service policy to VLANs and EtherChannel is described in the “Policy Associations”
section on page 44-73.
Qos Actions Numbers of entries supported
Classification 64k input and 64k output classification entries are supported.
A given policy can use at most 24k ACLs
Policing 16K policers are supported. Policers are allocated to given direction in blocks of 2k.
For example, 2k policers can be used in for input and 14k policers can be used for
output. Single rate policers uses one policer entry. Single Rate Three Color Marker
(srTCM) (RFC 2697) and Two Rate Three Color Marker (trTCM) (RFC 2698) uses
two policer entries
Marking Marking of Cos and DSCP/Precedence is supported through two marking tables, each
capable of supporting 512 entries. There are separate tables for each direction.
Queuing The queue size is Configurable with the maximum number of entries configurable per
port depending on the chassis and line card type.
DBL You can enable DBL action on all configured class-maps.