Top 5 Challenges with using Asterisk for your phone System

by Bryon D Beilman

In my previous post Top 5 Reasons to Use Asterisk for for your IP Phone system, I discussed some of the clear advantages to using the most popular and flexible IP phone system out there.  Ironically, I started with discussing how in the past, the early phone systems provided a high level of quality that was the baseline for all others to use.  IP phone systems do not have this reputation and by most users experiences are just the opposite of a quality call experience.  The IP based protocols that allow us to browse the web , get emails and even watch movies struggle with providing real time quality connections.  If your email is delayed by a few minutes, you may not notice and even most video services don't start streaming until they are sufficiently buffered, but talking to someone who is delayed or choppy in real time can be a very frustrating experience.

The power of the Asterisk phone system is real and is still a very viable option for your business, but the IP communications along with the open source nature of it can provide some challenges. Below are the top 5 challenges of using asterisk along with some ways to reduce that challenge in your implementation and hopefully avoid the typical implementation pitfalls.

1) Asterisk is Open Source  - There are commercial systems based on Asterisk (even from large companies like Dell), but the core of it is based on open source software.  If any of you have every worked with an active open source platform, you know that the versions can move quickly.  This seems to be the opposite of what you might need for a stable and reliable phone system. In order to implement Asterisk well, you need to treat it like a regular application and keep it up to date all the time. The primary reason for this is that if you ever decide to add a new feature to it (like a PRI or a POTS card) and you are not up to date, chances are the card you are adding will only work with the latest drivers and any support you need for that card will also require you to be "up to date".  If you don't touch your phone system for a few years because "it just works", you may have challenges if you want to enhance it in the near future.  Treat your Asterisk phone system like any other mission critical server and application and use good change management techniques to keep it up to date on a regular basis.

2) Distributions and Phones - There are numerous asterisk packages to choose from, but which one is right for you? There this FreePBX, Elastix, AsteriskNow, and Trixbox to name a few. The packages all use a version of Asterisk, which is essentially the phone engine and they all provide ways of configuring and managing the phone system. Most of them are done through a web interface, but it may not be easy to choose the one right for you.  To add to the complexity, there are many IP phones that are compatible with Asterisk, but the distributions may not have those phone models built in, so choosing the combination of phones and Asterisk distribution is an important decision.  How to get it working leads us to the next challenge.

3) It may require technical expertise - There are some very good distributions out there, but if you want to add a custom interactive voice response (IVR), configure a new Polycom conference phone or configure the modules for a new line card, you will most likely need to be versed in Linux and the details of where the configuration files live. The good news is that once it works, other than the upgrades mentioned in item 1, it should be easy to maintain.  If you have no technical expertise or do not have an IT consulting company that does it for you, Asterisk may not be the platform for you.  It may be more cost effective in the long term to use Asterisk, but be prepared to spend a little up front to configure it well and make it do what your business needs.

4) Solving issues when things go wrong - What do you need to do if your phone system has a problem? When you have a system that can do anything, what do you do when it doesn't work? Most people rely on a reliable phone system to be available for their customers and if your menu doesn't go to the right person, or the phone doesn't ring or forward like you expected, what is your next step?  This relates to item number 3, as  every step of an asterisk operation is recorded in a log file from getting an IP address, downloading an image, establishing a sip connection and making calls.   Knowing how to look at the logs and interpret them and find the solution can be tricky.  You can keep a technical resource/consultant available for these types of things or if you keep your version of Asterisk up to date , as mentioned in item 1, you can maintain a support account with Digium who can help you with configuration issues with the core Asterisk product.

5) Call Quality - Perhaps the biggest challenge people have with any IP phone system is to have consistent and high quality calls. Internal to the asterisk system, internal calls are rarely an issue and most of the problems relate to using an external SIP provider to make external calls or those who have remote external phones connecting to the Asterisk server.   Doing this well boils down to configuring QoS or protocol/bandwidth priority for the calls.  Some vendors only guarantee the quality if you use a dedicated circuit for phone service,but if this is not possible, then you need to make sure that your phone call does not get trumped by someone else on your network doing a large download.  If call quality is important to you, then you also need to invest in a firewall product that can to the prioritization that you need.

Asterisk can provide business quality phone service for your company, but it is important to spend your resources up front on configuration and the proper network equipment. The results of proper planning will be long term savings with robust enterprise type features that work properly so you can focus on your business.