Requirement of MBG for getting MiCollab for Mobile to work

[synthesis]

While trying to use MiCollab for Mobile to connect to MiCollab server after providing the authentication key, I got the following error:
Error Code: 22 - Connection to the MiCollab Client Deployment server denied. Cannot verify the security certificate. Please contact your administrator
Clicking on "More information" led me to this link:http://help.devices.mitel.com/help/index.html#22. In addition to indicating that only public trusted TLS certificates are supported, it mentions that certificates should be installed on MBG. What is the role of MBG for using MiCollab for Mobile? Is it mandatory to have MBG to get MiCollab for Mobile working? I am connecting to MiCollab server using a VPN so I don't understand why MBG would be required.

[dilkie]

the short answer. "Yes" it's mandatory to use MBG with Micollab mobile client... push notifications to the client require MBG.