OpenSIPS 1.6.1 is the first minor release of the 1.6 branch. This release contains mainly bug fixing (additional to 1.6.0) and some performance fixings - but no functionality, scripting or interfacing were changed.
OpenSIPS 1.6.1 contains important performance fixed related to memory (fragmentation) and registration (search speed) support - it is recommended to upgrade, as it provides important stability improvements - OpenSIPS 1.6.1 is now available for download on project web site and SF download system.
The full Changelog is available here.
To get the OpenSIPS 1.6.1 version, see the Downloads page.