Cisco Systems A9014CFD manual General QoS Limitations, Statistics Limitations, 24-26

Chapter 24 Configuring QoS

Configuring Quality of Service (QoS)

•Congestion Management Limitations

•Shaping Limitations

•ACL-based QoS Restrictions

General QoS Limitations

The following general QoS limitations apply to the Cisco ASR 901 router.

•You can create a maximum of 256 class maps including the class-default class map.

•You can create a maximum of 32 policy-maps.

The following limitations apply to QoS policies on HDLC, PPP, PPP interfaces:

•Input PPP interfaces support only QoS marking policies.

•You can create a maximum of eight match statements within a class map in a service policy applied to a PPP interface.

•You can create a maximum of eight classes within a policy-map that is applied to a PPP interface. This number includes the default-class.

•You can have only one priority class within a policy-map applied to a PPP interface.

•The match-allkeyword of the class-mapcommand is not supported.

•The following actions are not supported for Egress Policy:

–Bandwidth value

–Priority value

–Set of qosgroup (VLAN Priority)—This is relevant only for Layer 2 transport over MLPPP interface.

•Requires explicit configuration of class-default with bandwidth percent.

•DSCP marking is not supported for class-default queue.

•All the above restrictions are applicable to MPLS/IP over MLPPP, in addition to the following specific restrictions.

The following limitations apply to QoS policies on MPLS/IP over MLPPP interfaces:

•Cisco ASR 901 router supports the following features for MLPPP egress—DSCP marking priority, eight bandwidth queues, link fragmentation, interleave, and queue limits.

•Input policy is not supported.

•EXP marking is not supported for class-default queue.

The following limitations apply to GigabitEthernet interfaces:

•You can apply a maximum of 2 different service policies to GigabitEthernet interfaces

•You can only use the class-default class for HQoS parent service policies applied to egress Gigabit Ethernet interfaces.

Statistics Limitations

•Input service policies on the GigabitEthernet interface support statistics in bytes.

•PPP and MLPPP interfaces support QoS statistics in packets.

•Output service policies on the Gigabit Ethernet interface support statistics in bytes.

	Cisco ASR 901 Series Aggregation Services Router Software Configuration Guide
24-26	OL-23826-09