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.
Citel Technologies , A Voice over IP Phone company that provides VoIP Business Phone Systems. Its Main products include EXTender, PBXgateway, Upgraded Hardware Products, PBX platforms etc.