How does one build a voice over IP system? It’s easy with our alternative. All you need is one networked voice over IP call controller and IP phones.

• You attach the controller to the network at any point in the system—location does not matter very much, as long as it’s on a reasonably reliable connection. Most people install it in their data centers. It takes up all of 2U of vertical rack space.
• These controllers come with redundant, hot-swap hard drives and redundant, hot-swap power supplies. You can also install a second controller in some other place as a resilient alternate controller, so even catastrophic problems don’t bring down the phone system. These controllers are very inexpensive, so the addition of a second one is an insignificant additional cost.
  
• You install whatever telephone network connections you need into the controller by plugging T-1’s or PRI’s into a built-in controller module. The controller can accommodate as many as sixteen PRI’s or T-1 connections. There’s also built-in analog ports for the attachment of analog trunk lines. If you have two or more controllers you can make these telephone network connections redundant.
  
• Then you install IP phones on your data network or install analog phones on your existing analog wiring (the controller will support both IP and analog at the same time, because it’s also a complete conventional TDM PBX). You can use either Mitel phones or any SIP-compliant phone, because the controller will do MiNET as well as SIP communications at the same time. The analog phones are whatever you generally buy; the IP phones start with a low-end two line IP phone with a port to attach a PC (so you can use the existing data connection for the phone and the PC), a one-way speaker, four programmable keys, and three fixed-function keys: hold, transfer, and redial, and volume, ringer volume, and pager volume controls.
  

They then range up through business-class, multiline phones with 2-line LCD displays and full-duplex speakers


To high-end phones with built-in LCD screens, XML capability, programmable buttons, and speakerphones


…and even to a very low-cost phone that doesn’t look like a phone—but plugs into your existing color PC monitor and puts the phone applications up on the monitor

You can run the voicemail system that’s included in the controller or integrate a separate voicemail system installed on a separate server. Both of these provide a full-featured voicemail system that can be integrated with any email server. The second option fully integrates email and voicemail with fax, offers speech synthesis and other features.