Is the 2N IP system remote to the 3CX system - i.e. 3CX is cloud based.
We use 2N units on the same lan, work perfectly - caller pushes the button , ring group is picked up and you dial DMTF code to open the door.
Not sure if it works remotely to 3CX cloud, (unless you have site to site vpn). May help, on the setup you have SIP Proxy and SIP Registrar to configure,
There is no text message service for 3CX,
Founded in 2005, when VoIP was an emerging technology, 3CX has gone on to establish itself as a global leader in business communications.