We have Cisco Unified Call Manager 4.1 and have the 7920 cisco handset phones along with it. Since these are reaching their end of life very soon I have been looking into the two newer models of wireless handsets. Models 7921 and the 7925 which both say they are compatible with version 4.1. My question is when I try to add a new device (phone) inside CallManager these two phones are not one of the choices when I choose the device when adding a row. Do I have to have a patch isntalled in order to use these phones in the future?