In my last Focus Brief, I made the case for why the desk phone will eventually disappear – perhaps sooner than we think. I also recently posed this as a question on Focus.com, and was surprised to hear from so many who clearly have little use for their desk phone any more.

Ultimately, I believe that will be the end result, but desk phones do have a lot of life left in them. They also have a lot of utility, and so long as that remains true, we will keep using our desk phones. This Focus Brief provides counterpoint to the desk phone extinction scenario, with five reasons supporting their continued usage.

Reason #1 – PSTN is always there – works all the time and quality is great

There is no denying that after death and taxes, one of the few certainties in life is PSTN dial tone. Our legacy phone network may be old, expensive and short on innovation, but it works very well for what it was designed for. PSTN remains the gold standard for quality, reliability and scalability.

When VoIP first came to market, it was considered a hobbyist novelty, and never a serious alternative to PSTN. VoIP, of course, has come a long a way, and under the right conditions can approach parity with legacy telephony. Those conditions are not that common yet, but as SIP trunking gains momentum, things are changing. In fact, under ideal conditions, VoIP quality can surpass TDM, but that requires true end-to-end IP, and data networks that are fully optimized for voice.

In time, VoIP will reach its potential, but as long as voice remains our preferred mode of communication, the quality of PSTN calls will still carry great weight. While some voice traffic may be shifting to mobile, wireless networks are a long ways behind the PSTN for quality, and are not an immediate threat to displace landline telephony in the business world. We’ve all experienced dropped calls or poor quality with both VoIP and mobility, but very few of us can say the same for PSTN on the desk phone.

Reason #2 - Nothing beats picking up the phone and calling to get things done

Too much choice in any situation is usually a bad thing, and it definitely applies to the world of IP communications. It seems so long ago that everyday communication in business took one of two forms – meeting in person or talking on the phone. Today, we have far more options, with text modes being just as common as voice modes. Not only are we challenged in making good use of these options, but we now have the added layer of managing both business and personal communications. Technology advances cut both ways, and in this case, we typically use the same tools for both personal and business needs.

All of these variables give us more ways to communicate with more people with more frequency. Some people – I would contend very few – thrive with these choices, and learn to work more efficiently. Most of us, however, find all these choices stressful, making us slaves to technology. Aside from creating inefficiencies, this also depersonalizes the communications process, to the point where notices about sensitive issues such as layoffs or contract awards are sent online.

Short of meeting people face-to-face, there is simply no substitute for using the phone to convey an important message. The same holds for urgent communications. In some cases, IM can work well here, but when a point needs to be made in the moment, a phone call carries the most gravity.

Reason #3 – Phone system is a sunk cost, and is too expensive to discard

This is especially true for a PBX, although large scale key systems would also be costly. These phone systems rarely break down, and so long as they’re working well, it’s hard to justify getting rid of them. In cases where the capital cost has not been fully amortized, this will definitely be the case. It could also hold for older systems, where the business simply gets used to the utility of a resource that’s not costing them any capital dollars. Of course, they’re still paying monthly maintenance fees, so there is a cost for the status quo, but it may not be enough to change their mindset.

We’re still in a weak economy, and as long as the phones are working, the rationale here is going to hold in most cases. It’s fair to say that businesses with fairly old phone systems will likely have a legacy mentality around telephony. This means they think about telephony as a product – the PBX – and not a service. They also think of telephony separately from IT and data networks.

If VoIP and IP telephony are not high up on their radar, then the concept of shifting voice to run on a data network will not have much credence – and in that scenario, the PBX isn’t going anywhere until smoke comes out through the receiver.

Reason #4 – Familiar and comfortable – it’s all there

Old habits die hard, especially around telephony, which we all use every day. The phone is arguably the most familiar tool in business, and even though we spend more time with our PC – and maybe even our mobile devices – we’ve been using the phone for much longer. In some ways, the desk phone is like the fax machine – every office has one, and even though there are better options available today, both of these persist. The demise of fax machines has been ongoing for years, but they’re still widely used. By the same logic, the need for office desk phones has only recently come into question, and I don’t see them going away in less time than fax machines.

Another factor to consider is the familiarity we have the basic features. Phone systems that have been in use for years will have an established regime that makes internal communication efficient. Think about extensions, hunt groups, call forwarding options, programmed numbers on speed dial, etc.

Nobody really wants to start over with these, even though an IP-based system may give them more features of value, particularly for things they cannot do on a legacy system. While each vendor has its own way of doing these things, most IP phone systems can carry these features over seamlessly. True as this may be, the built-in inertia that comes with this familiarity will likely keep many of those desk phones around for years to come.

Reason #5 - Alternatives haven’t proven to be better

Ultimately, the desk phone will not disappear until something truly better comes along. In many ways, VoIP is better than TDM, but it’s taking businesses a long time to buy into that. When existing phone systems are working fine, it’s hard to convince businesses to make a change. Over time, those changes will come, but VoIP still has a long way to go.

The same can be said for phasing the phone out altogether, whether it’s TDM or VoIP. Desk phones still provide a lot of utility, as evidenced by the other reasons in this brief. In terms of alternatives, the main contenders will be mobility or PC-based telephony. Even with 3G, the quality and reliability of mobility is too far behind TDM – and arguably VoIP – to effectively displace the desk phone.

PC-based telephony is the more likely successor, in the form of either softphones or Web services such as Skype or Google Voice. Regardless, both lack the feature richness of a desk phone, and involve too much of a behavior change to occur in the near term.

This Focus Brief presents my counterpoint to the premise that desk phones are on the way out. I still believe this scenario will unfold, but old habits die hard and there several good reasons to support the opposite point of view. Ultimately, I see this being a generational transition, some of which I alluded to here, particularly reason #3.

In time, the Internet generation will dominate the workforce, and in this case the old habits won’t be tied to desk phones. For this group, their habits are much more Web-centric, and chances are they won’t even miss the desk phone when it’s gone. I’m not 100% sure this will be a good thing, but I think it’s inevitable, but at that point it won’t be my problem, and probably not yours either.