Voice Over IP is a much more cost effective means of transmitting voice vs. traditional phone services and is packaged as flat rate plans vs. the pay per minute plans of traditional telephone companies. Additionally, Hosted VoIP provides business phone system features like voicemail, IVR, voicemail to e-mail, hunt groups, etc without requiring expensive PBX equipment. These services are often referred to as Hosted PBX services and have made phone features traditionally reserved for large enterprises available to small and medium sized businesses.