IP PBX is a phone system utilising IP communications. Traditionally IP PBX's are located on site where they can also interface to traditional telco services such as analogue phone lines. The business end users connect via IP to the IP PBX for voice service.

Vendor Information

3CX - 3CX VoIP IP PBX
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Bullroar Telecom - Virtual PBX service from Bullroar is an all-inclusive hosted VoIP solution serving small businesses across the Gulf Coast. For one low monthly price per phone users have full access to a broad portfolio of features, virtually unlimited nationwide calling, and the reliability that comes along with our distributed nationwide network.
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Diamondcard Hosted PBX - Diamondcard Hosted PBX
Diamondcard Hosted PBX - Diamondcard Hosted PBX Wiki

Lean, mean and easy to use. We do initial configuration for you so its really easy to setup. Low cost and using open Source technology. Get started for as low as $9.60/mth. Reseller and private label program too. +1-303-997-0900 #1.

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.e4 Technologies - .e4 provides powerful, integrated IP Communications enterprise class services that provide the SMB customer to configure the exact voice, video, messaging and collaboration services they need in just minutes- all delivered on-demand.
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Ip-Pabx.comIP-Pabx.com - First of its kind Hosted IP Based Pbx system offering from A-Z Solution from one provider. Totally Hosted Web Based Pbx System, Very Low priced starting 199$. You place an order, choose your Country Code and Area code for your incoming lines, choose extension quantity, They ship you pre programmed 99$ ip phones, you plug them on the internet, and wala, you have a pbx system up and running. the extensions can be anywhere in the world, and they will work fine. ...