We will be going over how you can set up a hosted IP PBX for your small business office. The system we will be setting up can be scaled to a virtually unlimited number of IP Phones and an unlimited number of locations (all that is required is an internet connection). Not only that but the initial startup costs are minimal as well as the recurring costs. You will have to use the command line a few times to set this up, but it’s not too difficult to go through if you’ve never done it before.
Phone system equipment :
- Cisco IP Phone (Cisco SPA 504G – PoE powered)
- Linode VPS (Nanode 1GB)
- VoIP.ms or other provider SIP trunk
VoIP Phone System Overview
Here is a small network diagram we drew up to give you an overview of how the phone system will be set up.
Why Use a VPN?
You may have noticed in the diagram above the L2TP / IPSec VPN tunnel that we’ll be creating and using. Although it’s a little more cumbersome to set up, it is much more secure. Not only does this encrypt your network traffic, but also allows you to secure your IP PBX (hosted on Linode) completely. Allowing only VPN traffic allows us to close almost all ports, like 80 for HTTP, 22 for SSH, and 5060 for SIP, to outside connections. The downside is that you will have to manage your PBX through the VPN when changes or updates are needed. However, this isn’t too big of a problem to set up and we’ll show you how.