Tuning AutoQoS
AutoQoS might need tuning for three common reasons. First, it can configure
too many classes for your network needs. Second, it does not adapt to
changing network conditions. Third, it just might not include the types of
policies you want.
Some questions to ask as you evaluate the policies generated by AutoQoS
include:
■ How many classes were created using class maps?
■ What classification criterion was used to place traffic into each class?
■ What DSCP and COS markings were configured for each traffic class?
■ What types of queuing or other QoS mechanisms were implemented?
■ Was the policy applied to the interface, PVC, or subinterface?
AutoQoS Classes
AutoQoS uses up to ten different traffic classes, as shown in Table 5-1. The
table also shows the type of traffic included in each class, along with its
DSCP and COS markings.
Table 5-1 AutoQoS Traffic Classes
Traffic Class Traffic Type DSCP COS
IP Routing Network control traffic CS6 6
(for example, routing
protocols)
Interactive Voice Voice bearer traffic EF 5
Interactive Video Interactive video data AF41 4
traffic (for example,
videoconferencing)
Streaming Video Streaming media traffic CS4 4
Telephony Voice signaling and CS3 3
Signaling control traffic
Transactional and Transactional database AF21 2
Interactive Data applications such as SQL
Network Network management CS2 2
Management traffic such as telnet
Bulk Data Email traffic, general AF11 1
data traffic, bulk data
transfers
Scavenger Traffic needing CS1 1
less-than-best-effort
treatment
Best Effort Default class, 0 0
includes all other traffic
Too many classes might be generated for your needs. Most companies use
between three and six classes. You might want to manually consolidate some
classes with similar QoS needs after AutoQoS has finished its configuration.