Question : Problem: MAC address prefix (OUI) for Cisco VoIP phones

Does anyone know the OUI (Organization Unit Identifier) of Cisco VoIP phones?  This is the first three octets of a MAC address for a Cisco VoIP phone.

If you simply provide me with the full MAC address of your Cisco VoIP phone and the phone model number, I'll give you the points!

Answer : Problem: MAC address prefix (OUI) for Cisco VoIP phones

00-03-6b
this example of a cisco voip phone OUI can be found in this document from 3com
http://www.3com.com.ar/corpinfo/en_US/technology/tech_paper.jsp?DOC_ID=251284
Whether its an actual OUI or not is a guess, but I sincerely doubt anyone will give you the MAC address of their phone.