Hi all, we have OCS 2007 r2 up and working here (a lot of job has been made with MS integrations). This kind of product is able to forward external PSTN calls through a NON AUTHENTICABLE SIP TRUNK (there is no way to insert user and pw). My question is simple: can 3cx phone system accept this kind of sip trunking becoming my OCS2007 PSTN gateway? Do i need the enterprise version? How to do that? Thanks In advance. Diego.