We've purchased CISCO phones 7960 with SIP firmware to work with Asterisk PBX. Later we decided not to use Asteriks and purchased CISCO UC 540 instead.
But it turned out that the phones cannot register at CISCO UC 504. What can be done in this situation? Can we make CISCO UC to work with our phones?
Do we need to upgrade the firmware on the phones? If so are there any detailed instructions on how it can be done.