An on-premise phone system utilizes hardware & software which is located at a customer location – typically in an IT closet, break room or some other area of the business. These components go by a variety of names such as common equipment, CPU, KSU, SIP Server, PBX, etc.
Instead of using traditional telephone wiring, the VoIP PBX utilizes your existing computer networking to carry the voice traffic between your telephones and your on-premise system.
When using a VoIP PBX, your calls can still go through a traditional phone company as well as the ability to utilize Voice over Internet Protocol (VoIP) to take advantage of SIP Trunking. SIP trunking is yet another option for customers to obtain ‘dial tone’ services obtained from an Internet Telephony Service Provider (ITSP) rather than a traditional telephone company.