Hi

Thanks for suggestions, If we want to comply strictly with rfc 5853 in our SBC so we should have a B2BUA also int it.

What is your recommendation?

1-Using Kamailio/Opensips for forwarding REGISTER/SUBSCRIBE/NOTIFY to external Registrar and using a Freeswitch for media+B2BUA  ?

2-Using Kamailio/Opensips + rtpengine and just using Freeswitch as B2BUA in media bypass mode

Regards.

M.shirazi