A first network device forwards a plurality of packets to the one or more network ports for transmission to a second network device, wherein ones of the packets include a field for indicating different, independent types of information. A field populator is configured to, for each of at least some packets among the plurality of packets: determine, from a set of different, independent types of information, a type of information to be included in the field of the packet according to a schedule known by the second network device, and populate the field in the packet only with data according to the type of information determined according to the schedule.