I have spent multiple hours with IT trying to figure out why calls forwarded from one extension to another were not ringing the other extensions. Finally figured out that it's because those extensions were showing offline, and evidently the only way to show those extensions as "online" is to log in to the "Phone" app (the icon with a phone) on a desktop/laptop. If you try to login to the phone app with a mobile phone it makes you use the RingCentral app (the icon with an R) and it will not show the extension as being "online" if logged in with the RingCentral app. Only if logged in to the phone app. So in essence, there is no way to accept a call to a mobile phone through the RC app that is forwarded from another extension. This is a major/massive oversite with the RC app. One of the most basic functions of a phone system where I want to forward a call that comes into my extension to ring to my assistant's extension can't be done unless my assistant is sitting at her desk logged into the phone app on her computer. Ridiculous. They need to fix this asap. I am having to look for a completely new system/software that can do these basic things.