QoS implementation for VoIP network

Question

We are in VoIP business and running RTP/SIP traffic 80% in our network we have other servers also like www and monitoring and operation, our network is very flat and simple also we have very basic configuration on L3 switch and L2 switches, we are running couple of VLANs to separate traffic and everything running without QoS.

Now we are thinking to implement QoS because it's very important for real time protocols but have no idea how and what is the best practice to implement and do we really need QoS, there are many un-answered question i have and don't know how to start and where to start to implement QoS, so looking for expert advice or suggestion to see what we can do to make it better.

Following is diagram of network to give you idea.

Answer 1

QOS is something you will configure to treat some traffic (VOIP traffic) with priority better than other (WWW, monitoring ...), even call signaling can be treated with less priority than the VOIP payload itself.

implementation could be divided in two parts,

internally: between phones inside same network, which in your case is not needed at all, I can figure out it is 1G end nodes with 10G uplinks which is more than enough.

externally: in case of multi-site implementation where the VOIP traffic will traverse WAN connection with other normal data traffic. in this case you need to configure QOS as per a lot of recommendations and calculations (number of concurrent calls, the Codx you use in this calls). Also need to be mentioned that,

QOS in this case will be configured on the last place this VOIP traffic will leave in your network toward the other site, the WAN router for example.