Is open-source IP telephony dependable?
Perhaps your business has made the decision to upgrade to a premises-based IP telephony system. The question is: which route is best, proprietary or open source? Does your business choose a well-established supplier of proprietary IP PBXs or is it attracted to the often cheaper and more reactive route of an open source IP PBX? How important is the underlying hardware and software upon which your telephone calls will be made and received?
First we need to consider what is meant by ’open source’ in the context of IP PBX systems, so let us take an example: word processing applications, such Windows Word or Mac Pages, are proprietary applications as are nearly all the applications that a business will use on a day to day basis. That is, the behind-the-scenes source code cannot be amended in order to allow the implementation of any new features that may be required. This is an advantage is many ways as it is not often wise to allow anyone to amend software in this way – and therefore subsequently be responsible for retesting and supporting the amended version – as could be done if these applications were ’open source’. In other ways it may be a disadvantage, for example if a business really must amend the way an application works in order to suit special needs, this is not always possible when the software application is proprietary. In addition, as the development of open source systems is undertaken by a wide variety of people with a range of skill levels, and as open source software can run on relatively inexpensive off-the-shelf hardware, open source systems can be cheap. It’s a similar story for telephone systems: the operating system that controls an IP PBX’s may be amended, tweaked or re-written by anyone who chooses to do so – ‘open source’ – or alternatively, by design, it may not be modified – ‘proprietary’.
Open source IP PBX systems such as those based upon Asterisk, of which Digium-based systems have the lion share, have made some headway into the IP PBX arena. Although reputable proprietary systems often have a surfeit of functionality required by most businesses – such as click-to-dial, sophisticated in-bound call routing, automatic pop-up of CRM client details and the ability to make calls simultaneously via a number of interfaces – there is sometimes a need for businesses to tailor their telephone system in business-specific, non-standard ways. Or perhaps a business is forced to make cost the primary factor. So there can be a real and valid reasons to consider open source systems.
However, few open source systems are adequately able to support small to medium-sized businesses – certainly those who deem telephony as ‘mission-critical’ – as few systems can be scaled to cater for larger enterprises. Perhaps most important of all, fewer still can stand up to being rigorously tested and it’s often a challenge to obtain meaningful information on testing regimes and mean time between failure rates. In common with other open source applications, Asterisk-based systems are developed by a number of varying companies: there may be some advantages to this approach but these must be contrasted by the fact that no one system has significant enough market exposure to a large customer base over a protracted period of time. This can result in coding errors and security vulnerabilities remaining undiscovered and users finding themselves beta testers for what they may have been lead to believe were tested and released implementations.
For those businesses who feel they really must consider a highly-bespoke and non-standard telephony implementation it should be borne in mind that building and programming an Asterisk IP PBX is not for the faint-hearted; few businesses have the expertise to build a system in-house and so opt to purchase from Asterisk suppliers. In turn a robust support contract is needed which means making sure that the supplier that provides the Asterisk system is ’solid’ and will be around for the duration in order to provide any support you may require. Owing to the nature of open source systems there is rarely the option to rely on the back-up of a distributor or manufacturer. In addition, there are platform issues to consider: not every business runs Windows or uses PC’s.
Our best of breed premises-based IP PBX system from Zultys, however, provides client software that can run on a PC, a Mac OS X and Linux environment. This – coupled with the functionality, robustness and scalability that Zultys provide and their longevity and their many years of experience in IP telephony – makes Zultys our premises-based IP PBX system of choice. Long established since 2002 and developed in America’s Silicon Valley, Zultys are the best kept telephony secret in Europe!
Ask yourself this: would you be happy knowing that the software of the plane you’re flying on has potentially been amended by anyone when your life, and the life of everyone on the plane, depends upon its correct functioning? Or would you prefer for it to have been designed and tested by the manufacturer who built the plane? It is an extreme example perhaps but a parallel can be drawn here: telephone calls are often life-blood of a business.
Inexorably then, there seems to be a logical draw back to proprietary IP PBX systems, placing the open source systems to one side. Here at 500 we have considered open-source PBX systems – and we’ll continue to monitor the progress of Asterisk-based PBX systems and other emerging open-source IP PBX solutions – but of the three we have reviewed, all were ultimately found wanting. So, we must state that we believe that current open-source offerings do not truly provide mission critical business-grade telephony.
To find out further information on why or to talk to us on any other matter, please don’t hesitate to call us on 0845 0000 500.










August 12th, 2008 at 12:08 pm
I never thought I will agree with this opinion, but you know… I agree partially now…
August 12th, 2008 at 9:55 pm
Really interesting, i’m not sure when was the last time i eared something similar, but in general it’s a great idea, contratulations!…
August 13th, 2008 at 10:09 am
Thank you for your comments. It’s great to receive interesting and constructive feedback. All our articles are researched and given independent consideration and we are aware they are different to those posted on other sites. We are trying to provide prospective clients and the industry with realistic and relevant information not tainted with spin or sales pitch. We are glad you approve.
October 31st, 2008 at 12:35 pm
Productivity is definitely the biggest benefit of VoIP for businesses. Our research shows that most small business (less than 50 users) do not save much, if any money by moving to Voice over IP, although cost savings is the primary reason why most companies decided to make the move.
It is only after making the move to VoIP that a company begins to understand the potential of their new systems. Managers see the flexibility, ease of administration and ability to incorporate phone system changes quickly and inexpensively, do companies actually begin to reap the productivity of VoIP.
April 8th, 2009 at 10:23 am
As a follow-up ‘case in point’ note regarding this article, please see the warning post from the FBI below regarding an open source Asterisk vulnerability.
http://www.fbi.gov/pressrel/pressrel08/vishingpbx_120908.htm
http://chiefofficers.net/888333888/cms/index.php/news/comms/comms_industry_standard_asterix_voip_server_hacked