== SRTP unprotect failed on SSRC 1159450567 because of authentication failure 160
== SRTCP unprotect failed on SSRC 1336164530 because of unable to perform desired validation
== SRTP unprotect failed on SSRC 1159450567 because of authentication failure 160
== SRTCP unprotect failed on SSRC 1159450567 because of authentication failure
== SRTP unprotect failed on SSRC 1159450567 because of authentication failure 160
...
This was the kind of error I saw on an Asterisk system where we wanted SRTP. The vendor of the remote endpoint was using an older, faulty version of libsrtp (even on their most current firmware) and these encrypted calls were failing.
I believe the faulty version(s) of libsrtp are the 1.5.x versions… 1.4.x seemed to be ok and newer ones too.
Ask your hardware vendors about their SRTP library versions.