I have been using freeswitch with ZRTP successfully, and recently decided to do a pull from master. We haven't updated in a while, and I am testing how our current configurations work with the latest git pull. After the pull, my clients can't seem to establish a ZRTP session. Should I be doing this differently, or is there a new variable I need to be setting? I was under the impression that proxy_media would pass the media through unaltered, so I am a bit confused as to why this would change between versions. Previous version: (Version 1.5.8b git beb0673 2013-11-27 00:48:49Z 64bit) In this version I would look for a zrtp-hash, and if present I would simply proxy_media. <condition field="${endpoint_disposition}" expression="^(DELAYED NEGOTIATION)"/> <condition field="${switch_r_sdp}" expression="(zrtp-hash)" break="never"> <action application="set" data="proxy_media=true"/> </condition> Current version: (Version 1.5.14b git 5ea1729 2014-07-21 11:48:10Z 64bit) Using the same code as above, my endpoints do not negotiate ZRTP. Eventually my clients issue a hangup, since I have them set to require ZRTP for testing purposes. 2014-07-22 16:44:10.891255 [INFO] switch_channel.c:3304 sofia/shared/ sip:7kkklf@192.168.10.134:33588 Activating ZRTP passthru mode. 2014-07-22 16:44:10.891255 [NOTICE] sofia.c:7181 Channel [sofia/shared/ sip:7kkklf@192.168.10.134:33588] has been answered 2014-07-22 16:44:10.891255 [INFO] switch_core_media.c:5152 Activating RTCP PORT 0 2014-07-22 16:44:10.891255 [INFO] switch_core_media.c:5333 Activating ZRTP PROXY MODE 2014-07-22 16:44:10.891255 [INFO] switch_core_media.c:5152 Activating RTCP PORT 0 2014-07-22 16:44:10.891255 [INFO] switch_core_media.c:5333 Activating ZRTP PROXY MODE 2014-07-22 16:44:10.891255 [NOTICE] switch_ivr_originate.c:3494 Channel [sofia/shared/cueyeo@testcust] has been answered 2014-07-22 16:44:11.331267 [INFO] switch_rtp.c:5622 Auto Changing port from 192.168.10.134:60402 to 1.1.1.1:50944 2014-07-22 16:44:16.391257 [NOTICE] sofia.c:947 Hangup sofia/shared/cueyeo@testcust [CS_EXECUTE] [NORMAL_CLEARING] The only suggestions I can find on the wiki are at " http://wiki.freeswitch.org/wiki/ZRTP" which indicates that zrtp_secure_media and rtp-enable-zrtp needs to be set, which I have done.