VoIP QoS by Stream changed
The TCP Quality of Service (QoS) or precedence bit should be set to highest priority to ensure voice quality. If the precedence bit is changing, it could indicate a problem that will cause voice quality to plummet if there is any congestion on the network.
Possible reasons for this event:
The call manager is not configured correctly.
The IP telephone equipment is not configured correctly.
Switches, routers, or APs along the voice path are not configured correctly.