How to configure QoS for video

[Scott12]

hello everyone,

I have to configure qos on for video on the network, but unfortunately I have not found a guide to configure the qos for video,
My devices are, switches 2960, 3850 and ASA 5508.

If anyone can help, please advise.

Regards

[Joseph W. Doherty]

What kind of video?

If streaming, the main QoS functions are to avoid dropping any video packets and also to not unduly delay such packets too much (sometime several second delay is okay).

If interactive video, besides again avoiding dropping any video packets, allowed delay is much like VoIP requirements. If fact, for this kind of video, in principle, QoS treatment is very much like VoIP bearer requirements except the bandwidth demand, per flow, can be much, much more and individual packets might also be much larger.

QoS features, for your devices, should be detailed in your reference and usage guides. The Catalyst switches also likely support the AutoQoS feature (don't know if the ASA does).

Actual QoS configuration settings will also depend on your overall QoS policy (which your OP doesn't note).

If you can be more exact in what help you need, we can be more exact in providing help.

[Scott12]

Thanks for your time.

We would like to apply qos to skype for business and teams. I'm not sure what is the properly configuration regarding streaming.

What type of configuration do you suggest?

Regards

[Joseph W. Doherty]

skype, I recall, would be interactive video, so it should be treated as noted in my prior posting.

BTW, since you mentioned an ASA, would some of this traffic flow across the Internet?

[Scott12]

yes, that's correct.

[Joseph W. Doherty]

Ok, well first, for any traffic crossing the Internet, generally QoS isn't supported. Often (at least on Cisco routers/switches - again I don't know the capabilities of an ASA) you can prioritize traffic as desired upon ingress to the Internet, but as egress from the Internet is often also a common bottleneck, you cannot (again usually) arrange QoS there.

If you're a beginner at QoS, my two suggestions would be either to try AutoQoS, which might, or might not, deliver the results you need or begin a study of QoS so that you can use it to meet your service needs. QoS as a subject, really isn't difficult but it's a very broad subject. I.e., you need to understand a lot of it to really use it effectively.

For study/reference you might start here: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book.html

You can also read up on specific configuration guides (and/or perhaps technotes) on QoS for you devices. E.g.: https://content.cisco.com/chapter.sjs?uri=/searchable/chapter/content/en/us/td/docs/switches/lan/catalyst3850/software/release/3se/qos/configuration_guide/b_qos_3se_3850_cg/b_qos_3se_3850_cg_chapter_011.html.xml&searchurl=https%3A%2F%2Fsearch.cisco.c...

I'm sure you would appreciate a simple QoS "cookie cutter solution", but unfortunately, one size often does not fit all (and AutoQos isn't a bad one size solution, until it is a bad solution).

I.e. unsure I can assist you further w/o you being much more specific. However, if you do have additional QoS questions (often the more specific the better), post them. Many will try to assist.

[Georg Pauwen]

Hello,

in addition to the other posts, I would think that, since you use the ASA and that is probably the Internet facing device, the QoS would best be configured on the ASA. Skype uses the default DSCP values below, so if you configure your switches to trust the DSCP values coming from Skype, you can configure the QoS policy on the ASA as below. This is of course very generic, but might point you in the right direction:

Switch interfaces:

--> mls qos trust dscp

Skype for Business Signaling, DSCP 28, source port TCP 5060:5079

Skype for Business Audio, DSCP 46, source port TCP/UDP 50020:50039

Skype for Business Video, DSCP 34, source port TCP/UDP 58000:58019

Skype for Business Application Sharing, DSCP 24, source port TCP/UDP 42000:42019

Skype for Business File Transfer, DSCP 14, source port TCP/UDP 42020:42059

ciscoasa(config)# class-map SKYPE_BUSINESS_SIGNALING
ciscoasa(config-cmap)# match dscp 28
ciscoasa(config)# class-map SKYPE_BUSINESS_AUDIO
ciscoasa(config-cmap)# match dscp 46
ciscoasa(config)# class-map SKYPE_BUSINESS_VIDEO
ciscoasa(config-cmap)# match dscp 34
ciscoasa(config)# class-map SKYPE_BUSINESS_APPLICATION_SHARING
ciscoasa(config-cmap)# match dscp 24
ciscoasa(config)# class-map SKYPE_BUSINESS_FILE_TRANSFER
ciscoasa(config-cmap)# match dscp 28
!
ciscoasa(config)# policy-map SKYPE_PRIORY_POLICY
ciscoasa(config-pmap)# class SKYPE_BUSINESS_SIGNALING
ciscoasa(config-pmap-c)# priority
ciscoasa(config-pmap-c)# class SKYPE_BUSINESS_AUDIO
ciscoasa(config-pmap-c)# priority
ciscoasa(config-pmap-c)# class SKYPE_BUSINESS_VIDEO
ciscoasa(config-pmap-c)# priority
ciscoasa(config-pmap-c)# class SKYPE_BUSINESS_APPLICATION_SHARING
ciscoasa(config-pmap-c)# priority
ciscoasa(config-pmap-c)# class SKYPE_BUSINESS_FILE_TRANSFER
ciscoasa(config-pmap-c)# priority

!

ciscoasa(config)# service-policy SKYPE_PRIORITY_POLICY interface outside

[Joseph W. Doherty]

Again, I'm unfamiliar with ASA QoS capabilities, but in principle, I would be a bit careful about including ..SIGNALING, ..APPLICATION_SHARING and/or ..FILE_TRANSFER in a true "priority" class. (NB: Their DSCP markings all imply this being in the CS3/AF3x group.)