CUPS 1.2 device auto detecting

[anonymous]

In the web GUI of CUPS 1.2.0, add printer will invoke 
/cups-1.2.0/backend/snmp.c to detect printers in the network.
Per my understanding, snmp.c will do the following:
1. CUPS uses SNMP device type and device description OID to broadcast and 
detects printers

2. CUPS tries to determine connection URI. It tries various URIs, in the 
sequence of IPP, socket 9100, then lpd

3. If the device support IPP, it will then request printer-make-and-model 
IPP attribute from the printer.

As printer information has already be aquired using SNMP in the first step, 
and the support for SNMP is way better than IPP (some printers support IPP, 
but might not support all the IPP attributes), should CUPS just using SNMP 
sysDescr to match PPDs?