I plan to implement the QoS policy below.
- The target is to garantee bandwidth to VOICE and CRITICAL traffic.
- It should be 1/3 for Voice and Video, 1/3 for Business Critical traffic, 1/3 for all the rest.
- If one of the classes don´t use the reserved bandwidth, the other classes can take it.
- I would like to make sure OSPF is running fine even the when the links are congested to avaoid flappings etc.
The plan is:
- Parent policy to shape to 20Mbps
- Child policy to apply QoS for 1/3 Voice/Video, 1/3 Business Critical, 1/3 all the rest
The Questions:
- I read somewhere that routing protocol traffic gets automaticcally into the LLQ, thats true? If not, how i can make sure the OSPF traffic in outbound direction originated by the SW itself is priorized and gets transmitted even if the link is overloaded?
- Is the approach in my policy right to do what i descriped above? Or do i have some mistakes inside?
Open for tipps, tricks, critic, hints
Setup
- OSPF is running on both links where the policy should be applied
- Traffic is already marked by hard / sofphones for voice and video
- Platform where QoS should be implemented is Cisco 4500X running in VSS
PLANNED CONFIG
class-map match-any CM_QOS_VOICE-VIDEO-TRAFFIC
description Matching voice, voice signalling, video and app-sharing traffic
match dscp ef
match dscp cs3
match dscp af41
match dscp af21
!
class-map match-any CM_QOS_CRITICAL-TRAFFIC
description Matching critical traffic: Routing Protocol, Business critical, etc.
match access-group name ACL_BUSINESS-CRITICAL-TRAFFIC
match access-group name ACL_ROUTING-PROTOCOL-TRAFFIC ! Necessary or automatically put to LLQ?
!
policy-map PM_QOS_SHAPING-20M
class class-default
shape average 20000000
service-policy PM_QOS_WAN-EDGE
!
policy-map PM_QOS_WAN-EDGE
class CM_QOS_VOICE-VIDEO-TRAFFIC
priority percent 33
class CM_QOS_CRITICAL-TRAFFIC
bandwidth percent 33
class class-default
fair-queue
random-detect
!
interface te1/1/1
service-policy output PM_QOS_SHAPING-20M
!
interface te2/1/1
service-policy output PM_QOS_SHAPING-20M
!