10-03-2017 12:46 PM - edited 03-08-2019 12:14 PM
Hi All - I'm hoping to verify my understanding of QoS is correct.
I'd like to enable QoS for media and call signaling as much as possible throughout our environment. Our call center connects to a 2960x stack attached to two 2911 ISR's with MPLS connections up to our datacenter where our UC cluster is housed.
Currently the plan is to enable QoS on all access ports and uplink ports with the "auto qos trust dscp" command. We're going to use Group Policy to tell our end devices (running Jabber) to mark dscp. So my questions are...
1. Is enabling "auto qos trust dscp" across all network gear the right way to do this?
2. Should we use dscp all the way, or is there a reason to convert dscp to CoS?
3. Any "gotchas" or things we should watch out for?
Catalyst 2960-X Switch QoS Configuration Guide, Cisco IOS Release 15.0(2)EX
Cisco Jabber 10.6 Deployment and Installation Guide
10-03-2017 02:07 PM
"Auto" under Cisco is great when you are working with Cisco products/services so go for it based on their documentation.
In this case, I believe that configuring it across the board on the expected traffic path will serve you well. Obviously...test it out and see what happens. In most cases, you do not have to worry about the dscp values but under a stressed network (a lot of traffic, etc), it might be prudent to make sure that those values guarantee your critical applications' traffic.
10-04-2017 08:35 AM - edited 10-04-2017 08:43 AM
#2 avoid using L2 Cos, use L3 DSCP whenever possible.
#1 and #3 Well, usually Cisco's auto QoS protects VoIP type traffic. For the rest, it depends whether their QoS model is suitable for your needs. If you're going to do more than protect VoIP over BE traffic, you should review the auto QoS settings and determine if it's what you want.
It's easy to make things worst with poor QoS policies. Don't assume Cisco's auto QoS might not make things worst - much depends on your actual traffic.
10-04-2017 09:42 AM
Thanks Joseph. #2 Can you elaborate on why we should use DSCP over CoS?
10-04-2017 09:45 AM
10-04-2017 09:51 AM
Okay, that makes sense.
So we only have VoIP traffic requiring QoS (Cisco IP Phones, Jabber for Windows, Webex, Telepresence units such as MX800). We don't have any other critical or timesensitive traffic. I did review the auto-QoS documentation and it looks like it will do what I need, I was hoping for a second opinion on here though. From what Packetherder said I'm feeling good about it. Do you have the same thoughts?
10-04-2017 12:49 PM
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