By Deb Shinder
Tuesday, May 29 2007 09:27 AM
URL: http://www.zdnetasia.com/insight/communications/0,39044835,62013086,00.htm

As the lower cost of calls--particularly long distance and international calls--attracts more and more companies, VoIP's popularity in the business world continues to grow.

According to iLocus Research's annual report on the VoIP industry (which the company has been tracking since the late 1990s), the IP PBX market grew 52 percent from 2005 to 2006, and the number of worldwide voice over broadband (VoBB) subscribers (both consumer and business) almost doubled.

Those growth statistics are impressive, but a look at actual percentages tells a different story. Less than half of businesses use VoIP, and less than a quarter of small businesses do so. If cost savings are so dramatic, why haven't more companies -- especially small ones that don't have millions invested in their traditional phone systems -- made the switch?

In 2006, VoIP Magazine predicted that half of all small businesses and two-thirds of large businesses would be using VoIP by 2010 -- although not necessarily exclusively for all their telecommunications needs. To get there, VoIP providers are going to have to overcome the obstacles that have so far prevented many businesses from cutting the telco cord and moving to IP-based phone services. Let's explore some of these obstacles.

Reliability concerns
The performance of the long-established public switched telephone network (PSTN) has "spoiled" telephone users. While consumers and employees accept that computers sometimes go down, their expectations of the phone system are much higher. When they pick up the phone, they expect to get a dial tone. Users won't tolerate less than rock-solid reliability from their telephone systems.

Companies depend on the phones to stay in contact with customers, partners, and vendors -- as well as within the company for communication between employees. A phone outage can bring business to a halt -- or, at the least, slow it down considerably and cost the company big bucks.

VoIP is far more reliable than it was just a few years ago. However, there's still a perception of unreliability that providers must overcome before cautious managers will take the plunge.

And there's another aspect to reliability. The regular phone jacks in a building don't require electric service to work (although equipment such as PBX does). That means you can still have phone service during a power outage.

VoIP depends on both electrical power and Internet service. Interruption of either means losing phone service. You can ameliorate the problem by having redundant Internet connections and power backup such as a generator, but this adds to the cost.

Network quality of service
VoIP is far more sensitive to network "glitches" than data transmission is. If the network drops data packets, it just resends them. If the dropped packet results in an e-mail delayed by a few minutes, users likely won't even notice.

But if delays in transmission or dropped packets cause a disrupted phone call, you can bet the call participants will notice -- and complain. The data transmission process is much more transparent; because phone calls are real-time communications, problems are "in the face" of the users.

IP networks are subject to many variables, including:

• Packet loss due to network congestion or corruption of the data
• Variation in the amount of delay of packet delivery, which can result in poor voice quality
• Packets arriving out of sequence, which can result in discarded packets and cause more delay and disruption

In addition, the analog-to-digital conversion process can affect VoIP call quality, causing users to experience unpleasant distortion or echo effects. Another culprit is signal level problems, which can cause excessive background noise that interferes with conversations.

To help prevent such problems, the IP network must support quality-of-service (QoS) mechanisms that allow administrators to give priority to VoIP packets. This means a VoIP network is more trouble to manage than a data network, and it requires a higher level of expertise -- or at least an additional skill set -- on the part of network administrators.

VoIP monitoring and management solutions are available that make it easier to optimize voice services, but that adds to the cost of deployment. It also negates some of the cost savings that motivate the move to VoIP in the first place.

Complexity and confusion
The complexity and unfamiliar terrain of VoIP communications presents another big obstacle for many companies. Network administrators well-versed in running a data network may not know much about how VoIP works, what equipment is necessary, or how to set up and maintain that equipment.

In addition, VoIP terminology quickly gets confusing -- media gateways, analog telephone adapter (ATA), audio response unit (ARU), interactive voice response (IVR), etc. Company managers and IT personnel hear about different VoIP protocols -- H.323, SIP, IAX -- and don't understand the differences or know which one they need.

Already overworked IT staffs may not be eager to undertake the task of learning a whole new specialty nor the added burden of ongoing maintenance of the components of a VoIP system. They may not be sure how to integrate the VoIP network into the existing data network.

Of course, there are answers to these problems. Consultants with the requisite knowledge can help set up a VoIP network, or companies can use hosted VoIP services to reduce both the complication and the upfront expenses of buying VoIP servers. However, once again, this ups the price tag of going to VoIP and eats into the cost savings that are one of VoIP's main advantages.

Security
Finally, reports on the security vulnerabilities of IP networks have bombarded companies, and the risk of intercepted calls and eavesdropping are a concern. In addition, providing another layer of vulnerability to a data network integrated with the VoIP network is also a worry.

While malicious users can tap traditional telephones, it's a fairly difficult process that usually requires physical access -- at least for anyone other than a government agency. Traditional phone communications travel over dedicated circuits controlled by one entity -- the phone company. But when VoIP packets go out there into the "Internet cloud," they go through numerous routers and servers at many different points.

Encryption and other security mechanisms can make VoIP as secure or even more secure than PSTN. But once again, it's perception that matters. (And, of course, extra security mechanisms mean extra cost.)

Summary
VoIP is gaining ground steadily. However, before it becomes ubiquitous, the technology needs to overcome some obstacles. VoIP providers must not only address the problems of reliability and quality of service, but they must also reduce the complexity and confusion inherent in implementing VoIP and address security concerns. And, at the same time, they must keep VoIP costs lower than the costs associated with traditional phone service.

Deb Shinder is a technology consultant, trainer, and writer who has authored a number of books on computer operating systems, networking, and security. She currently specializes in security issues and Microsoft products, and she has received Microsoft's Most Valuable Professional (MVP) status in Windows Server Security.