Symptom
When you enter the "mgcp ip qos dscp cs3 signaling" CLI command in global configuration mode, the parser returns "% Ambiguous command: "mgcp ip qos dscp cs3 signaling "" and the command is not applied correctly to the running configuration. Instead, the default DSCP setting for MGCP control traffic is being used which is DSCP AF31.
Conditions
ISR 4k with IOS-XE V16.8.1ES4
Workaround
Use a service-policy in outbound direction as a workaround to mark outgoing MGCP control traffic with DSCP value CS3.
