Kamailio version 4.0 brings a lot of improvements and new
features to the leading Open Source SIP Server. Here's a
few examples of the core new features in this major release
(and the reasons we're releasing a 4.x series upgrade):
* End of Kamailio – SER integration: In the 3.x release
series, Kamailio and SER shared the core source code, but
there was duplicated modules and different database
structures. Now the project is back to one set of modules,
with all the duplicated modules having been integrated.
There's now one set of modules, not three.
* New transport layer: Starting with this release,
Kamailio supports the WebSocket transport layer (both
plain and secure), in addition to UDP, TCP, TLS and SCTP.
WebSocket support (as outlined in an IETF draft with one
of the Kamailio developers as co-author) allow modern Web
using SIP for signaling.
* Kamailio is the default application name (aka, default
flavour), what the project is packaging. SER can be built
manually, and the "SER" flavour is kept for historical
and maintenance reasons.