Small Business PBX Part 1 - Coming up with a plan

I'm in the process of setting up my first PBX at a company I work for! This article will serve as a reference for me and hopefully others looking to setup something similar. Before getting into all the details on the installation I'm first going to walk through the current network and telephony configuration. I'll then detail how I made

Current Network and Telephony Configuration

The network this PBX will be running in has several desktops and laptops on a Windows Small Business Server 2011 domain which is running as a guest on a 2008 R2 Hyper V server. Running the SBS server as a virtual machine was done because the business also has several remote users which connect using Remote Desktop Services. This normally would require an additional physical server but with Hyper V, both the domain controller (SBS) and the terminal server (2008 R2) were able to run on the same server. In addition to the terminal server and domain controller, there is also a Windows 7 virtual machine for testing purposes so it makes a lot of sense to add the PBX as a fourth virtual machine.

The current phone system consists of two lines running into the main office, the main line is connected to a cordless phone system with four handsets and the secondary line is connected to a Konica Minolta multi-function for faxing with two handsets plugged into it. The two handsets connected to the multi-function are used for outgoing calls while the four handsets on the main line are used to answer incoming calls. When an incoming call takes to long our customers get send to voicemail which has lately been happening far to often.

Lastly, we are in the process of setting up another office in the back of the building. This office currently has a single phone line running to it but will need an Ethernet line as well to support a couple desktops.

Upgrade Plan

The upgrade plan calls for the following:

1. Minimal expenses
2. At least one more line needs to be added so incoming calls are not going to voicemail
3. We still need a fax line
4. In the event of a power outage we still need to be able to make calls
5. Outgoing calls should preferably always be made through the fax line regardless of where the caller is located so as to not tie up the main line (even if they're in the new office in the back of the building)
6. An auto-attendant to answer calls and forward them to the correct extension
7. Separate voicemail boxes for individual employees

Based on the last two items a PBX of some form was required. The first four items suggested that an open source software PBX running as a virtual machine and connected to our existing analog lines ($15/month with unlimited long distance) would be the way to go. This would mean the only additional costs would be for the extra line, and the time to setup the system.

I then set out to choose an open source software PBX and find a way to connect our existing analog lines to it.

Choosing a PBX

See Part 2 of this article.