Oracle have taken a positive step of blocking Unsigned Java RIAs (Rich Internet Applications) in the latest version of Java, this is a good idea from a security point of view (more details here).
Sonus have a great Real Time Monitor view on the gateway web interface that relies on Java. It shows the real time status of trunks and calls.
Unfortunately in earlier version of Firmware (2.2.1 and below), the Java application was not signed. Previously not a huge issue, you would be warned it was unsigned and prompted to allow it to run.
However with the latest version of Java installed, by default an unsigned application will simply be blocked, with no option to allow it to run.
If you are running an older Sonus firmware and need to allow the application to load you can reduce your Java security level from High to Medium (not a great idea usually) or add an exception for the gateway by IP or DNS (better). To do this go to Control Panel/Java and add the site to the Exception Site List. You will then be prompted to allow the loading.
Fortunately in the latest 3.x Sonus firmware Sonus have signed the Java application so you will be prompted to run the application correctly. There is no need for this workaround. Also 3.x opens up the REST API for free which allows some really nice management and configuration options.
Incidentally the Microsoft network Test TRIPP tool has the same challenge and same solution.