A new module named SCA is now available in the development branch of Kamailio, to be part of the next major release. The module was developed by Andrew Mortensen, from University of Pennsylvania, USA.
SCA (Shared Call Appearances) handles SUBSCRIBE messages for call-info and line-seize events, and sends call-info NOTIFYs to line subscribers to implement line bridging. The module implements SCA as defined in Broadworks SIP Access Side Extensions Interface Specifications, Release 13.0, version 1, sections 2, 3 and 4.
You can read more about the module at: