We had this issue logged with Ruckus six months ago and have already upgraded twice on the advice that the next firmware up will fix VOIP issues and this will be the third upgrade so I am very skeptical as to whether this will actually work.
Have you any documented evidence to prove the upgrade will fix our issues or is it just a case of 'We don't know so upgrade'?
You're point it well taken. While 9.6.2 has a number of generic VOIP fixes that *might* address your issues, there are also environmental, and best-practice guidelines that must be taken into account. Here on the forums, it's not practical to address all of those complexities, and so the best course of action is to open (or re-open) a support case to make sure all variables are addressed.