This target allows to alter the value of the DSCP bits within the TOS
header of the IPv4 packet.  As this manipulates a packet, it can only
be used in the mangle table.
.TP
.BI "--set-dscp " "value"
Set the DSCP field to a numerical value (can be decimal or hex)
.TP
.BI "--set-dscp-class " "class"
Set the DSCP field to a DiffServ class.