Very Cool

What isn’t obvious until you get to the very end of this article is that it's written by the CEO of a company that develops IP PBX software. It's hardly an objective analysis.

Let's look at the so-called benefits one by one:

1. Much easier to install and configure than a proprietary phone system: the guilty secret here is that most IP PBX systems are themselves proprietary -- especially those provided by market leading companies. Yes, there are some open source IP PBX projects -- but at this stage these do not have either the robustness or feature richness required to support a serious business enterprise.

As to the suggestion that IP PBXs are easier to configure and install, maybe that’s the case for a 5-extension simple system…

The market leading IP PBX (it's marketed as a unified communications system) is extremely feature-rich and reliable but more complex to install than a traditional TDM PBX! When set up to support, for example, a contact centre operation, it can sometimes require 10 or more servers to be installed and integrated. The technical skills required to complete this work are extensive and expensive. From real world experience, I can vouch for the fact that such an implementation is at least as complex as would be required to implement the same features and functionality using traditional TDM technology.

2. Easier to manage because of web/GUI-based configurations interface: the author suggests that the web-based configuration interface or graphical user interface is only available to the IP PBX. This is simply not true. Many traditional TDM PBXs have supported graphical user interfaces for system management for more than 10 years.

3. Significant cost savings using VoIP providers: once again, the author suggests that a particular benefit is only available to users of IP PBXs. Users of traditional TDM PBXs can take advantage of VoIP services using either an external interface boxes or internal IP interface cards.

4. Eliminate phone wiring: real-world experience shows that it's almost always better and more reliable to use a separate port on the data switch and separate wiring for an IP phone. This allows quality of service (the bugbear of IP phone installations) to be effectively managed all the way to the telephone. If the desktop PC is connected to the network through the IP phone (or vice versa) there is a very real risk that data traffic to and from the PC will interfere with voice traffic to and from the phone. Since most offices and workstations are wired with multiple category five cables these days and ports on data switches are very cheap, sound practice dictates that separate phone wiring is the norm even in an IP PBX environment.

5. Eliminate vendor lock in: has the author never heard of analogue telephones? In a traditional TDM PBX, user organisations always have the option of an analogue phone if they want something cheap or to avoid a vendor lock in. Today's SIP phone in the IP PBX world is just like the analogue phone in the TDM PBX world. Just as analogue phones did not deliver the full range of desktop functionality that was available on a proprietary digital phone, so SIP phones do not deliver the full functionality that is available from the market leading IP PBX systems: full functionality requires the manufacturer's proprietary IP phone. One other thing is worth noting: SIP phones are significantly more expensive than the analogue phones of old. So it may be possible to avoid vendor lock in by using SIP phones, but don't expect to save money compared to using the analogue phones of the past. And don't forget to ask your IP PBX vendor about the availability of analogue interfaces for fax machines, lift phones, door phones, modems or any other legacy applications. These can be cripplingly expensive.

6. Scalable: growth in system size presents challenges in both the IP and TDM worlds. In both cases, there are hardware and software breakpoints that must be crossed when a business grows. Careful planning up front can ensure that sufficient infrastructure is installed on day one to avoid encountering such breakpoints in the reasonably foreseeable future.

7. Better customer service and productivity: the author is talking about Computer Telephony Integration -- the ability to integrate the data in computer systems with the functioning of the telephone system. Such functionality has been available in the TDM PBX world for 15 years. To claim this as an exclusive advantage of the IP PBX is simply untrue.

8. Twice the phone system features for half the price: once again, this is simply untrue. Cheap IP PBX systems simply do not have the feature richness of traditional TDM systems. Real-world experience (ask any of the companies who have actually implemented and IP PBX system) is very clear: you don't buy an IP PBX system to save money up front. The purchase price for a full-featured, fully installed communications system is pretty much the same irrespective of whether the system uses IP or TDM. Systems using many proprietary telephones are often more expensive in the IP world.

9. Allow hot desking and roaming: hot desking has been available in the TDM world for more than 10 years. It's not necessary to re-patch the wiring when somebody moves to a new desk. Either the system administrator can use a graphical user interface to make a software change or, in many systems, the user can enter a code into their phone to transfer their programming to the new desk location. It is certainly easier to set up roaming and to allow working from home using IP technology: but this can still be done using an IP interface card installed in a traditional TDM PBX.

10. Better phone usability -- SIP phones are easier to use: no they're not. In fact, on most systems, SIP phones will have lower functionality than the manufacturer's proprietary IP phones. It's simply not in the manufacturer's interest to make it possible for users to access the full range of functionality from a phone for which the manufacturer will get no revenue. If it makes sense to reveal telephone functionality by augmenting the telephone with a PC (as the author suggests), then this can be done on a TDM PBX using an analogue phone. Real-world experience suggests that most users do not like to work in this way -- they want access to the full range of functionality irrespective of whether the PC is switched on or switched off, and they don't want their PC applications pushed to the background by the phone system.

Just because I am debunking this author's claims doesn't mean that I don't believe in the future of the IP PBX. I do. I firmly believe that the traditional PBX will have almost vanished from the new systems market within the next five years: IP PBXs certainly do have some advantages and the architecture does offer important flexibility for businesses as they grow and change. But let's not kid ourselves. Businesses make these large capital purchase decisions based on careful analysis. And based on that analysis, many businesses will find that their in situ TDM PBXs have many years of faithful, reliable and feature rich performance yet to deliver.

This puff piece on IP PBX technology does very little to advance the cause. Read with care.

Some great points Richard, thanks.