iPhone ZRTP support

Question

I'm using Freeswitch ( with ZRTP enabled ) + OpenVPN tunnel.

When extensions call each other without zrtp everything is working fine.

When enabling ZRTP on both iPhones ( with Zoiper payed software ) and extensions calling each other the SAS shows right, when confirming SAS the SRTP icon get' s green but there is no sound. When I turn of ZRTP the sound is working. 

Answer 1

Please try to disable the STUN (it is recommended to do so if you use VPN). Also, keep in mind that both parties should confirm the use of ZRTP, if the second party did not accept it yet, then no audio will be played.