UC QoS for MPLS wide area networks
The Office Communications Server codec (RTAudio), is known for being capable of handling network issues and the avoidance of “jitter”. In my experience I would have to say in most cases this is true, however for a large-scale deployments that utilise modern day MPLS networks QoS (Quality of Service) or CoS (Class of Service) are recommended.
Most MPLS networks rely upon DSCP (DiffServ Code Point), a field in the header of IP packets used for classification – in this case to prioritise and ensure call clarity.
Assuming you have already confirmed with your WAN vendor (in my case BT) that DSCP traffic priorities are configured and the appropriate allocation of bandwidth is assigned you next need to get tagging!
To classify all voice traffic you need to configure both clients (where voice originates) and servers (where voice terminates) to generate DSCP markings. For documentation on this review this excellent article over at TechNet.