Previous stable version was 5.1.x, see what was new in that release at:
This is a draft of new features added in this version, manually updated, thus not always synchronized with what is new in source code repository.
Generate accounting records in JSON format.
KEMI interpreter implementation for Python3.
KEMI interpreter implementation for Ruby.
Database APIv1 implementation with a REDIS backend.
IMS IPSec implementation for P-CSCF systems.
Presence User Agent implementation with JSON messages.
event_route[sipcapture:request] { if(src_ip==1.2.3.4) { sip_capture_forward("sip:2.3.4.5:5090"); return 0; } }