Kamailio & Asterisk as SBC


We study the possibility to integrate Asterisk as SBC and as voice and conferencing solutions integrated to kamailio.

The purpose of projet is to implement a VoIP secure solution with Kamailio as core IMS network.

In this project VoIP call will be established with zRTP. SBC is transparent for zRTP call, zRTP is establish between 2 end point (terminals). However for conferencing service we need to establish zRTP session with conferencing server (MRF).

Question related to voice and conferencing solutions :
In case of using Asterisk conferencing solution, is it compliant to ZRTP ? if not have you roadmap related zRTP integration ?
An other way is to custom conferencing service for our need. According to your knowledge is it possible ? (can you assist our developpement team to this customization ?)

Question related to SBC :
In case of using Asterisk SBC solution, the major problem is the failed over mechanism in case of Asterisk SBC malfunctions : all on-going calls are ended, immediately.
Is there failed over mecanism between SBCs Asterisk ? (or is it suported by Kamailio core Network ?)

Thanks you in advance for your answer