Why might 7941 phones configured the same as working 3905s not work?

Question

Telephony

There is a configured cme, works with cisco 3905 phones via sip. New 7941 phones arrived, set up by analogy with the old ones, on cme the latest firmware for these phones. The phone boots up, catches the address, firmware and number. There is a call to him, but there is no outgoing call, there is silence in the receiver. After a while, a message about registering the phone appears and it reboots. So constantly.

Answer 1

try to take the Cisco 7961/7962 config from here and do manipulations with it as described below on the topic
compare with yours