By now voice over IP(VOIP) is a common feature in most office phone systems. The majority of office phones in operation today use some form of VOIP between the desk phone and the private branch exchange (PBX). However, most phone systems still use traditional methods of connecting their PBX to a service provider using methods such as PRI’s (Primary Rate Interface) or a bundle of standard telephone lines.
Recently we made the decision to switch to a total VOIP solution for our office phones. This means that we reach our service provider through a SIP connection (Session Initiation Protocol) over our office internet connection.
There are many advantages to using SIP over traditional connections, as well as some downsides, so you need to weigh your options carefully before making a decision.
The Benefits of SIP Connections
One of the first benefits is the savings on your service provider fee. Typically with a PRI you pay a flat fee for the connection itself, and then a fee for every channel (or phone line) you have on the PRI. With SIP connections you usually pay per channel, but typically don’t pay for the trunk itself. An example of savings on PRI vs SIP services is outlined below (based on full 23 channels per PRI):
[table id=2 /]As you can see the savings on the circuit costs are around 45%.
Another benefit is equipment savings. For most moderate setups your office PBX can be hosted as a virtual machine or appliance, which is typically much cheaper than purchasing a physical appliance (either a gateway or a full blown physical PBX). This also allows for high availability (if you have the infrastructure for it), without purchasing backup PRI circuits (as your backup system would need spare PRI circuits connected in a traditional setup).
Pricing on PBX systems can vary wildly based on the number of users and feature set needed, but you could estimate at least $3000 for a new brand name PBX installed and licensed, with support costs being another several hundred dollars per year.
Disadvantages of VOIP Connections
There are some disadvantages to VOIP connections, as they typically share bandwidth with your other Internet traffic, and are also subject to factors outside of the control of your service provider as the Internet is public. Typically only minor issues arise when using the Internet such as some echo once in a while or the odd dropped call, but it is something you have to accept if you want to use VOIP.
We decided to take the plunge and switch our phone system over to VOIP and started down the path. We decided to use an Asterisk based system for our PBX (Asterisk is an open source system that has a very robust feature set if you are willing to learn to use it. We did some research and determined our existing phones would be compatible and decided to use this system.
Next update I will discuss the initial setup of our PBX and connecting our existing phones to it during the testing phase. Stay tuned as we make the journey to VOIP and detail some of our experiences along the way.
