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IP Telephony Unveiled Review by A. Sardella
Good Context for Voice/Data Convergence
IP Telephony Unveiled by Kevin Brown (Cisco Press, 2004) provides some interesting history of the convergence of voice and data, and points out how early efforts in this area were focused on the PBX; it turned out this was not a good place to converge because the links were inadequate for ever-increasing data traffic. Eventually the tables were turned and now it's apparent that the data network is the place to converge the two traffic types.
The book discusses new capabilities and applications: virus alerts, paging, etc. And it implies throughout that many more revolutionary ("killer") applications are still to be conceived. I kept asking myself if I was convinced of this, but there weren't enough true-ringing examples to sway me. Of course, the day has dawned for IP telephony (IPT). There's no question that toll bypass and unified messaging-with its undeniable cost savings and the means to increase employee productivity and hold staff accountable-will drive a very high growth rate in the coming years. I also think that video, with highly similar requirements (more bandwidth but nearly the same service quality) to pure voice over IP (VoIP), will be another business driver, but the book doesn't touch on this in any detail.
For the CxO or IT manager, there are some interesting pointers on selecting PBX features to implement in an IPT environment. It's interesting how simple-seeming features are implemented differently from one company to the next-call transfer is a classic example. This poses both a difficulty and an opportunity for IP telephony-standards are very nice things, even if there are sometimes too many of them, and IPT is inherently less proprietary than PBX technology.
I found the insisted-upon difference between IPT and VoIP (VoIP is just the traffic and IPT is the whole solution including clients, users, etc.) to be a bit of hair-splitting. In practice, these are used interchangeably and I don't see this resulting in any serious misunderstanding or lack of awareness of the potential of this technology.
There is a nice rundown of various PBX features such as profiles, authorization codes, time-of-day routing etc. It's easy to see the advantages of integrating these applications via softphone onto the PC. And the book points out that IP phones, though slightly harder to use because they're so feature-rich, lend themselves to simpler rollout and training than you get with a PBX, because the solution can be deployed incrementally like any new network application.
Yet I think there is inadequate defense of a couple of key rollout drivers. Ongoing maintenance costs-such as the ability to perform moves, adds, and changes-are indeed lessened with IPT as the book points out, though this was not the case only a couple of years ago, and IT management probably still needs convincing on this point. It also is fairly recently that folks are accepting that the data network provides the same reliability as a PBX based phone system, and this is also a perception that account managers still need to disabuse to get their sales.
The book does a nice job differentiating PBX from IPT architecture-IPT is both revolutionary and evolutionary, and is not private, nor branch-specific, nor an exchange. In a sense, phones are just another client, and IPT is evolutionary in this sense. IPT provides all the advantages of a PBX, and allows new applications to emerge. It partly does this because of how easy it easy to merge with the web and office applications on the PC-thus the book details the notion of speed URLs, which are similar to speed dials that we're familiar with on our everyday phones.
In the last chapters, the book focuses on the "vital few" initiatives that lead to a successful rollout, and on return on investment (ROI) issues. It stresses finding the value proposition and understanding the business. There are different issues for different markets, with one common thread in that sophisticated users, who drive markets in early stages, want the same intelligence for their phones that they currently enjoy on their workstations or personal digital assistants. Maximizing ROI is a matter of driving down network, administrative, and maintenance costs, while creating applications that focus on key company initiatives. Convergence logically extends the call control platform instead of requiring (in the old paradigm) a PBX in each location. This is where I would have liked to see more on call server deployment options, such as distributed versus centralized call processing, or clustering servers over a WAN.
And this is a choice that an author faces when writing a business book about technology-how much of the technology to include when you are focusing on the business benefits. My personal preference would have been to see more technical examples, because ultimately these details illuminate the marketing-oriented points of view. This is why I would give the book four stars out of five, with the caveat that if you are not a novice to IPT or you are looking for more meat on the real issues of deployment, it's more of a three. If you need an introduction with a strong sense of historical context, it's arguably a five, though it shouldn't be your only resource before engaging a vendor and working out the nuts and bolts of your IP telephony solution.There is some good technical advice towards the end-the author stresses the importance of an infrastructure that can handle voice. This section talked about some of the key "gotchas" to watch out for: lack of WAN bandwidth and over-utilized routers that might have trouble handling the Quality of Service (QoS) capabilities to ensure delay and jitter are within end to end limits for acceptable conversation. There are also some tips on planning the pilot and ensuring you have some voice expertise in house.
Provocatively the book ends by pointing out how little anyone foresaw the quick impact of the web and the productivity enhancements of connectivity and opines that increased convergence of voice and data may turn out to be just as catalytic. Again, I'm not personally convinced of this-I remember other grand promises-the paperless office, artificial intelligence-that fell short of the mark. In this sense, IPT is both a little less and a little more than the author implies, because the cost savings are a no brainer and this is one of the few certain high-growth areas in networking today.