It is the business practice of sending all clients' billing info to a separate company, who then does everything for you. It also allows a company to cut down on time and human resources spent on administrative tasks.
Snom One plus
Snom ONE plus is a telephone system (PBX), based on SIP protocol, designed as a universal hardware solution, which includes various options for connecting to PSTN: using analog, PRI (E1, T1, J1), BRI ports. When used with the Snom IP-phone it is a reliable and easy to install solution.