QoS of Voice and *Video*

[Rolando Valenzuela]

Hello Community, I was trying to came up with "the ultimate" QoS settings considering VoIP and Video on a 1Gb interface but the documentation for Video is confusing, attached a few tables as a reference.

It looks there's some overlap for what traditional is considered signaling (dscp af31) and RTP (dscp cs5) - I was wondering if that is because there's of the obvious overlap between voice and video or complete different technologies/protocols as explained by the Cisco (Multimedia Streaming and Broadcast video)

Additional recommendations for my "ultimate" settings will be appreciated.

Thanks!

Rolando A. Valenzuela.

R2(config)#class-map match-all VOICE
R2(config-cmap)#match dscp ef
R2(config-cmap)#match dscp c5

R2(config)#class-map CALL_SIGNALING
R2(config-cmap)#match dscp cs3 
R2(config-cmap)#match dscp af31 ! Old marking 

R2(config)#class-map VIDEO
R2(config-cmap)#match dscp af41 ! Video conference
R2(config-cmap)#match dscp cs4 ! TelePresence
R2(config-cmap)#match dscp af31 ! Multimedia Streaming
R2(config-cmap)#match dscp cs5 ! Broadcast video

R2(config)#policy-map LLQ
R2(config-pmap)#class VOICE
R2(config-pmap-c)#priority 20000 ! 20 MB 
R2(config-pmap-c)#exit
R2(config-pmap)#class VIDEO
R2(config-pmap-c)#bandwidth 10000 ! 10 MB
R2(config-pmap-c)#exit
R2(config-pmap)#class CALL_SIGNALING
R2(config-pmap-c)#bandwidth 5000 ! 5 MB
R2(config-pmap-c)#exit
R2(config-pmap-c)#class class-default
R2(config-pmap-c)#fair-queue

R2(config)#interface GigabitEthernet 0/0
R2(config-if)#service-policy output LLQ

Reference:

https://www.dslreports.com/faq/13324

https://networklessons.com/quality-of-service/qos-llq-low-latency-queueing-cisco-ios

[Leo Laohoo]

All I can say is QoS and 1 Gbps link is not a good idea.
Why? What kind of real-time application is capable of chewing an entire 1 Gbps link?

[Dennis Mink]

most providers will map your DSCP values into IP precedence anyway.

if you are using cucm, check the enterprise parameters to see what the dscp values are used, your QoS config, does not seem to set any dscp, based on acl on the ingress, so you pretty much trust all dscp that is coming in. typically you see ACL defining for instance RTP and setting dscp to ef, in which case it makes no difference what your devices set dcsp to.

[Rolando Valenzuela]

You are correct Dennis, in this case the phone itself and/or the access switches are marking the packets and then I trust that. This will be on the router right before a WAN or ITSP.

Attached are the CUCM configuration, does this should be my guideline for my markings?

Thanks!

Rolando A. Valenzuela.