режим работы с ТСОП(Public switched telephone network (PSTN) usage records specify a class of call (such as internal, local, or long distance) that can be made by various users or groups of users in an organization)
шлюз SIP / ТСОП(A device that translates signaling and media in different formats between the Enterprise Voice infrastructure and a public switched telephone network (PSTN) or private branch exchange (PBX))
