Use the “ip precedence” command to configure the value set in the IP precedence field when voice data packets are sent over the IP network. This command should be used if the IP link utilization is high and the QoS for voice packets need to have a higher priority than other IP packets. The ip precedence command should also be used if RSVP is not enabled and the user would like to give voice packets a higher priority over other IP data traffic.
This command only applies to VoIP peers.
Example
The following example sets the IP precedence at 5:
dial-peer voice 10 voip
ip precedence 5
source: Cisco