Core Issue
Cisco AutoQos is a Cisco IOS Software feature that automatically provisions Cisco IOS QoS features for voice traffic for Cisco router and Cisco Catalyst switch platforms.
Cisco AutoQoS automates consistent deployment of QoS features across Cisco routers and switches. It enables various Cisco QoS components based on the network environment and Cisco best-practice recommendations. With the increased prominence of delay-sensitive applications (voice, video, and other multimedia applications) deployed in networks today, proper QoS configuration ensures high-quality application performance.
You must have a thorough understanding of various QoS features (such as queuing, dropping, traffic conditioning, queue-depth, drop thresholds, burst parameters, LFI, and cRTP) and the complexities of configuring many parameters associated with these features. Cisco AutoQoS helps overcome these difficulties by automatically configuring the device for Cisco QoS features and variables with the correct parameters.
Users can subsequently tune parameters that are generated by Cisco AutoQoS to suit their particular application needs.
Cisco AutoQoS VoIP feature is supported only on these interfaces and PVCs:
- Serial interfaces with PPP or High-Level Data Link Control (HDLC)
- Frame Relay Data-Link Connection Identifiers (DLCIs)(point-to-point sub-interfaces only)
- ATM Permanent Virtual Circuits (PVCs)
This table shows the availability of Cisco AutoQos:
| | Platforms | Software |
|---|
| Switches | Cisco Catalyst 2950EI Cisco Catalyst 3550 | Cisco IOS Software Release 12.1(12c)EA1 |
Cisco Catalyst 4500 | Cisco IOS Software Release 12.1(19)E |
Cisco Catalyst 6500 | Cisco Catalyst Operating System 7.5.1 |
| Routers | Cisco 2600/2600-XM Series Cisco 3600 Series Cisco 3700 Series Cisco 7200 Series | Cisco IOS Software Release 12.2(15)T |
Resolution
These sample configurations show the same Cisco IOS configuration, first with AutoQoS and then with manual configuration techniques:
Cisco AutoQoS:
interface Serial0
bandwidth 256
Ip address 10.1.61.1 255.255.255.0
Autoqos voip
Manual QoS:
interface Multilink1
ip address 10.1.61.1 255.255.255.0
ip tcp header-compression iphc-format
load-interval 30
service-policy output QoS-Policy
ppp multilink
ppp multilink fragment-delay 10
ppp multilink interleave
multilink-group 1
ip rtp header-compression iphc-format
!
interface Serial0
bandwidth 256
no ip address
encapsulation ppp
no ip mroute-cache
load-interval 30
no fair-queue
ppp multilink
multilink-group 1
class-map VoIP-RTP
match access-group 100
!
class-map VoIP-Control
match access-group 101
!
policy-map QoS-Policy
class VoIP-RTP
priority 100
!
class VoIP-Control
bandwidth 8
!
class class-default
fair-queue
access-list 100 permit ip any any precedence 5
access-list 100 permit ip any any dscp ef
access-list 101 permit tcp any host 10.1.10.20 range 2000 2002
access-list 101 permit udp any host 10.1.10.20 2427
access-list 101 permit tcp any host 10.1.10.20 2428
!
access-list 101 permit tcp any host 10.1.10.20 1720
access-list 101 permit tcp any host 10.1.10.20 range 11000 11999
The show autoqos interface command is available to verify the actual QoS configuration commands provisioned by configuring AutoQos.
For more information, refer to these documents:
