3850 switch - using Diffserv to mark traffic for QoS

[KMNRuser]

Forum,

We are wanting to know if we can use our 3850 access layer switches for marking packets from our VoIP phones for QoS?

The current version of software we have running on our 3850's is:

LOUSERSWT#sho ver
Cisco IOS XE Software, Version 16.09.06
Cisco IOS Software [Fuji], Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version 16.9.6, RELEASE SOFTWARE (fc2)

Thank you!

[Joseph W. Doherty]

Should be possible.

VoIP phones cannot?

[KMNRuser]

Joseph,

I am being told that they cannot.  Thanks for asking.

Would the configuration to tag the VoIP traffic be:

class maps > policy map > service policy on egress interface?

Thanks,

Kevin

[Joseph W. Doherty]

Egress and/or ingress interface.

BTW, if your VoIP devices are on their own VLAN, class class-default with a set command might be all you need.

[KMNRuser]

Joseph,

Thats just it.  We are being told that these phones are not Vlan capable so they will simply be in the local user Vlan, which i dont quite understand.

[Joseph W. Doherty]

Ok, then you'll need a class-map which likely will new to use an ACL reference.

[Joseph W. Doherty]

E.g.:

access-list 102 permit udp any any range 16384 32767
access-list 103 permit tcp any eq 1720 any
access-list 103 permit tcp any any eq 1720

class-map match-all voice-signaling
 match access-group 103
class-map match-all voice-traffic
 match access-group 102

policy-map voice-policy
 class voice-traffic
  set ip dscp EF
 class voice-signaling
  set ip dscp CS3

[KMNRuser]

Joseph,  

Thank you for the configuration.  It is much appreciated.  I know when tagging we are supposed to tag as near to the source as possible, but in this instance would we apply this to the VLAN interface outbound (egress)?

Thanks,

[Joseph W. Doherty]

You could.

[MHM Cisco World]

QoS for 3850 can be 
ingress Marking and classification 
egress only Queuing 

please make double check the slide I share.

@KMNRuser  use in port direct connect to host (PC, IPone...etc.), and the value will be same when packet egress from other port 

[Joseph W. Doherty]

Oops, I believe @MHM Cisco World may be correct, i.e., the 3850's QoS support is more limited than later gen switches.

[MHM Cisco World]

[KMNRuser]

That is quite the awesome template!  Thank you!  I am not sure why it does not list the 3850's though..

[MHM Cisco World]