How to configure a basic QoS policy

Learn how to configure a basic QoS policy on your Cisco routers. A detailed example is provided along with a diagram that is easy to understand.

configure qos quality of service

In this example, we will configure a basic QoS policy in a scenario that is commonly used. The WAN interface is configured for bandwidth of 10 Mb, and the WAN connection is through a private ISP network (such as an MPLS connection).

The objective is to build a basic policy that will:

  • Put voice traffic in a Priority Queue and give it strict priority of 10% of interface bandwidth
  • Give SSH a minimum bandwidth guarantee of 20% of interface bandwidth
  • Give web traffic a minimum bandwidth guarantee of 20% of interface bandwidth

Configuration:

class-map match-any Voice
match ip dscp ef
match protocol rtp audio
class-map match-any Management
match ip dscp af31
match protocol ssh
class-map match-any Web
match ip dscp af11
match protocol http
match protocol https
!
policy-map LAN_in
class Voice
set dscp ef
class Management
set dscp af31
class Web
set dscp af11
!
policy-map WAN_out
class Voice
priority percent 10
class Management
bandwidth percent 20
class Web
bandwidth percent 20
class class-default
fair-queue
random-detect
!
interface GigabitEthernet0/1
service-policy input LAN_in
interface GigabitEthernet0/0
service-policy input WAN_out

 

Notes:

  • If your WAN connection is with a provider and not point-to-point, you must use the DSCP markings that they have configured to use for your traffic
  • You will have to configure the same on the Branch router for communication in the other direction

 

For any questions or further explanation, please feel free to leave a comment below or ask me in the forum.

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