PBXes supports currently Secure-VPN via VPN only. It can however cause troubles because not every hard- and softphones work with it. An easy and futureproof way would be an optional SRTP/TLS encryption with ZRTP Keyexchange as well, if possible.
Asterisk 1.8 already supports SRTP.
If it is important for you as well, please vote for it here:
We need it also.
For us security is important and VPN is not supported on most devices. It is also inconvenient to disconnect after a call. Plus after VPN is disconnected we cannot receive secure calls.
Thanks.
This post has been edited 1 time(s), it was last edited by mmz on 27.02.2011 at 00:18.
I have spoken to the developer of the sopftphones "phoner lite".
(In this softphone are both SRTP and ZRTP implemented).
He said, if both of them are activated PBXes (generally Asterisk) should work with it. SRTP alone won´t work.
The first tests show that normal conversations are possible also with clients which does not support SRTP / ZRTP. I must make some additional test with and audio records with clients which support ZRTP to see if it works.
Summary: all the clients which supports both SRTP and ZRTP seems to be compatible with PBXes.