I have a customer running CUCM 7.0(2). They are complaining of a very peculiar problem that is happening intermittently. They report that while in a conversation with another person, if they accidentally speak over each other at the same time, the RTP stream sorta pauses (or cuts out) and the think the call dropped, but then after waiting a few seconds they can hear each other fine. Myself and other engineer's have checked and double-checked the QOS configuration and everything looks fine. Besides, this problem is not happening when only one person is speaking at a time. ONLY when they accidentally speak at the same time. The only thing that I might attribute this problem to is a recent phone firmware upgrade to 8-5-2, but I really don't think that is causing any problem.
Has anyone ever heard of such an issue? I am completely puzzled. Any help or suggestions are greatly appreciated.