We have some old Cisco VoIP phone on our company. We tried to change original SCCP firmware to SIP (cmterm-6901_6911-sip.9-3-1-SR1-3) using tftpd64 software.
The firmware changed successfully. But in 6911 model we have a problem that phone doesn't get phone number and in phone web access it shows N/A for phone DN.
We don't have this problem with 7821 and other models. We tried the same SEPmy_phone_mac.cnf.xml for both.