How to Deliver Asterisk as a Service

The traditional hardware-based phone system is dead! Well, maybe that’s an overstatement, but the rise of open-source software-based PBXs is shaking things up. One of the major advantages of an open-source PBX system is you can deliver it to the client as a service. With the code provided by the open source model, you have the ability to create custom solutions for your clients’ needs as well as avoid the high cost of licensing typical with traditional PBS systems. You immediately get the attention of an SMB client when they learn the features of a $30,000 PBX can be delivered as a service with very little money upfront.

As an example, my company offers a bundled local, long-distance and PBX service. The PBX is still located on premise, but we charge for it on a monthly basis along with the network services. We add a 100 percent hardware warranty and service on the PBX server for the life of the contract. Software upgrades and any PBX troubleshooting are included. We also include 24×7 monitoring of the carrier router, client firewall, PRI circuit and phone server.

To go to market with such an offer, one of the first decisions you¬¬ need to make is whether to provide your own support or purchase a vendor-supported product. We chose to go in-house using freely available open-source products, because we have been running Linux-based systems for many years and have a very strong in-house support staff. However, turnkey systems, such as Switchvox from Digium Inc., Trixbox from Fonality Inc. and several others exist if you’re not comfortable with supporting the systems under the hood.

Many open-source options also are available for the core engine for your PBX. Our choice was to go with one of the most active development projects around, Asterisk by Digium. New features constantly are being developed for the Asterisk platform, and there is a large community from which to derive support.

Standardizing on your configuration is another key element in successfully delivering a stable platform to your clients. We typically start with a PRI circuit from the carrier, which is connected to a Digium T1/PRI card in the back of our server. In addition, we standardized on IBM as our server vendor because its gear is engineered for the enterprise and is supported by a wealth of published technical information. We also selected one model from within the IBM product line as our core solution. This has greatly reduced our troubleshooting when problems arise.

Next, you need to procure your PBX server platform. We recommend sourcing from reputable companies that specialize in off-lease hardware. Since the servers typically have been running in a data center for the duration of the lease, you can be confident they are in good working order and have been well maintained. The costs will be far less than purchasing new hardware and depending on the server manufacturer, you may still be able to obtain warranty support. Additionally you will have the opportunity to purchase spare units should a production box suffer a failure. You can find off-lease systems by searching the Internet. What are you looking for? A typical server for a 25- to 50-user environment, for example, requires a dual PIII with 2-4GB of RAM and 18–26GB of hard drive space.

Now that you have your server hardware, you need to load the operating system and PBX software. We chose CentOS, the community enterprise operating system, based on its stability and support. The PBX software is comprised of Asterisk core with FreePBX and Trixbox Web interfaces. Asterisk supplies the core functions and FreePBX and Trixbox provide the GUI and feature sets that make the system easy to administer.

At this point you’re ready to add phones. Any SIP-compliant phone will work, but spend some time reading online user forums to find posts about others’ experiences to narrow the field. And ask your client how they use their phones; that can influence the selection. For example, some clients rely on the use of the speakerphone a great deal, but the best all-around phone may not be the best speakerphone. We like the GXP-2000 from Grandstream Networks Inc. for all around price and features. The 57i from Aastra Technologies Ltd. makes a great high-end phone with advanced features like an XML-based API, wireless handset option, “sidecar” expansion module and ease of setup.

In many cases, making the sale will come down to whether or not the client has to rewire their office to support the phone system. To prevent this from becoming an issue, we select only phones that have an Ethernet pass-through jack on them. This means the existing drop to the PC can be used for both the PC and phone. Preferably you would have separate drops and networks for the phone system and the data network for security and performance reasons, but that’s not always possible due to your client’s budget.

Consider the power requirements of the phones, switches and PBX server to ensure the proper battery backup solution is in place to support the phones during power outages. We typically engineer for a 50 minute or greater run time on the phone system. Also determine whether the client will run a generator on the premises in the event of a power outage. Not all battery backup systems support generator power.

You also have the ability to add a business continuity option to your solution by placing a failover PBX in your data center. Should the client facility lose connectivity for any reason, you can forward their numbers from the carrier switch to your recovery PBX, which is mirrored every night from the production PBX in the client office. Users can take the office phones home or to another location, connect them to the Internet and they will re-register with the recovery server. This recovery solution is another place to build recurring revenue for your business while providing your clients with a feature that would be cost prohibitive with the traditional PBX solution.

The hosted on-premise solution provides your business with predictable revenue, continued growth and limits client churn while allowing your clients low-cost entry to the high-end PBX features their businesses require. We have been using the managed service model for both IT network and telecom services for two years with great success. This model has allowed us to provide high service levels to our client base, and we see great potential going forward.

Glenn Hall is the president and CEO of PlanNet Technologies Inc., which was founded in 1995 to deliver technology solutions to the small business market space. He has more than 20 years experience in information systems and has held IT positions from programmer to vice president in several Fortune 500 companies, including Bank of America, Chase Manhattan and Merrill Lynch.