We are using two Freepbx servers at out office and having 200 extensions configured on each. These PBXs are not interconnected.The first PBX is used for external calls and second for internal calls. Each user is given two extensions(one each from the two PBXs).
However, my softphone having two extenions configured from each PBX is able to make conference calls(3 way conf) involving calls on both extensions. And I need to prevent conference of such type.
I can’t think of a way to stop that, because (from the server’s perspective) it isn’t a conference call. Your not bridging the calls through the servers, you are bridging them at the extensions.
I’d contact the softphone provider and find out (from them) if there’s a way to prevent three-way calling or extension conference bridging. There may be a setting in the config that you can turn off/on that makes these kinds of calls not work.