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.
Level 3 (Nasdaq: LVLT) is an international communications and information services company and is headquartered in Broomfield, Colorado. The company operates one of the largest communications and Internet backbones in the world.