The autodiscovery addon to the collections system is on the release notes of 3.1 said to be a contrib. The autodicsovery is not a contrib it is a part of NAV. It is of cource not compulsary to use.
UiT has made a radius module to NAV for their own purpuses. This is running at their NAV installation. They are planning to submit the radius module to contrib for the NAV 3.2 release.
UiT has made a windows machine name collector (collects netbios name). A table containing IP addresses and netbios names is maintained. Scheduled for NAV 3.2 contrib.
UiT has also made expansions to the NAV service monitor. This includes a radius monitor. This is also scheduled for the NAV 3.2 contrib.
NAV third party solutions
MailIn: Andreas Solberg, UNINETT, has made a third party solution that interprets incoming email from external systems and posts events on the NAV event queue.