Hi all. I have a customer running 3CX who sometimes has calling problems because the trunk becomes unregistered from our Broadworks platform. When you look at the REGISTERs, there are a couple peculiarities: 1. 3CX sends an un-REGISTER (expires=0) right before it re-REGISTERs rather than just re-registering the session 2. 3CX sometimes, but not always, starts a new session (new Call-ID) for the "new" REGISTER rather than simply refreshing the existing session 3. Not a problem, but something I find odd and worth mentioning is that it sends the User-Agent info when it un-registers but *not *when it registers The problem comes in when we get the un-REGISTER but it is not followed by a new REGISTER and calls begin to fail. The customer is obviously frustrated and is expecting *me *to do something about it, but.... Anyone familiar with 3CX and can give advice? Any idea why it behaves this way? They're running v16.0.5.619 (based on #3 above). Thanks in advance. -Pete