QoS

[toolshed1]

Hi,

We are about to implement 300 devices that will be using Voip.

I have a general understanding of QoS and traffic shaping, but was looking more for real world advice as where to begin. 

[Francesco Molino]

Hi

First of all what type of devices are you implementing. QoS config is different based on device model.

The advice is to make sure that your config is aligned end to end (tag, queueing,..)

Make sure also when traffic pass some equipments like firewalls, to trust the dscp.

[toolshed1]

it will be about 350 android devices that will be connecting to our WAPs for voice and messaging.

Prob is that we didn't really profile anything yet as far as understanding if they will even saturate our links or not.

We have all Gig connections on access layer and 10 gig uplinks to L3 distr.

[Francesco Molino]

Ok then your talking also about wireless qos. This has to be inline with wired qos config.
On wireless you have also to take into consideration wmm. If your app supports you can also configure it.
Before moving forward, i recommend that you read cisco live presentation regarding wireless and wired qos.

[Joseph W. Doherty]

"real world advice" you only "need" QoS where there's congestion, that's adverse to your applications service needs, when QoS can help. However, network usage can suddenly change, so QoS might also be deployed even when not currently needed to help insure if it becomes needed, it's already in place.

"real world advice" much of current QoS literature often provides QoS much more complex than needed.

"real world advice" link saturation, or lack there of, don't always reflect the need for QoS.

"real world advice" wireless creates a new set of issues because the wireless is effectively like hub based shared wired networks. It's QoS features have not really been "wrung-out" much in the "real world".

[toolshed1]

thanks.

Another issue I might have is that I only monitor MEC uplinks to Dist on access switches. I don't monitor access ports