PBX (Non-public Department Exchange) — In a business, a phone exchange or maybe a switching program that allows a company with multiple cellphone extensions and features share a link to your PSTN. In addition, it allows inside extension-to-extension calling along with inbound and outbound calls. IP Phones and VoIP telephone http://messiahkoprq.collectblogs.com/13856771/voip-services-an-overview