Client device types via SNMP
I am currently using Cacti to do some historical graphing of some of our ZoneDirector data via SNMP: Client count, unique clients, that sort of stuff. One item that I would like to begin graphing is the types of devices (Windows, Android, iOS, etc.) that are connecting to our system.
While I can see that there's a pie chart widget available on the ZD Dashboard to show the client type, I'd like to know if it's possible for these numbers to be obtained via SNMP polling. I know that I can gather a good bit of info about client connections (what VLAN they're on, Tx/Rx stats, and so on), but in my snmpwalks, I haven't seen anything that really looks like a device type designation?
Is that info stored anywhere in SNMP? If so, where can I find it?