You can IF you put in between a Session Border Gateway. This is not natively supported within 3CX and you will drive 3CX nuts if you tried.
OR, you can setup one instance of 3CX on one server to operate as a Class 4 switch, meaning that all of the other 3CX will have bridges to it and IT will be the only one interfaced with the Patton.
I must disagree with you. Currently the term Class 4 and 5 switches refers to the feauture sets offered. In general a Class 4 switch is used in trunk or carrier services while Class 5 offers the more "end-user features". I certainly did not want to bring into play the SS7/TDM as it's outside the scope of the question. At present you will find that most VoIP providers (Wholesale as in SIP trunking) use Class 4 switches to merely swap SIP traffic.