Johannesburg — South Africa's long-delayed entry to the VOIP market has one major advantage for companies that have waited for legalisation. The technology is now so well understood that many of the technical challenges and obstacles users might have encountered earlier, have now been overcome.

The fact that VOIP is a fairly mature technology means that local companies and consumers can enjoy stable, state-of-the-art service without living through the teething problems experienced by those who adopted the technology earlier.

Many companies may be surprised to find that some of their existing equipment is already VOIP-ready: the only obstacle to using this capability has been regulatory. Now that hurdle is about to disappear, we can expect to see a flood of new VOIP implementations and applications on the market.

There are two key questions you should ask of a would-be VOIP supplier to make sure you get the full benefit of the knowledge that has been accumulated over the years. The first: is the equipment your vendor proposes to supply SIP-compliant?

SIP, or Session Initiation Protocol, is the key emerging standard in the VOIP market and looks set to replace the older (and still current) H.323 standard. SIP phones are already being mass-produced for the US and other consumer markets, and the increasing availability of SIP-enabled PABXs is driving enterprise adoption. The use of SIP is set for exponential growth over the next few years.

One of the main advantages of SIP is its potentially seamless integration with the existing telephone network. Unlike some other VOIP solutions which require both parties to have the same equipment or software, a user can call to and from any SIP phone to any number in the world - both SIP numbers and conventional telephone numbers.

In addition to ordinary calls, SIP allows for call forwarding under various conditions (always, when busy, when not answered, etc), for users to be reached under the same number at various different locations and using different devices, multicast conferencing and more. It gives both callers and callees a high degree of control over their preferences: for example, SIP could allow a call to be completed only if the callee (as opposed to his or her voicemail system) is actually available to talk. SIP also allows for "click-to-call" functionality on Web pages, where clicking on a hyperlink initiates a telephone call (this depends on the right software or hardware being available).

Some have described VOIP at the moment as being like the World Wide Web in the mid-1990s: nobody is yet sure what applications will be dreamed up to take advantage of the capabilities it offers. What is more or less sure is that most of those applications will be SIP-dependent: so, if you want your system to be able to keep up with developments in the next few years, make sure it's SIP-compliant.

The next question to ask is whether your provider is willing to implement a pilot or proof-of-concept project before proceeding to a full VOIP roll-out. Although one of the chief motivations for a VOIP conversion is to lower costs, the cost benefits alone should never be the sole basis of a decision - they should first be compared to the quality that can be realised.

This is particularly important because users are accustomed to exceptionally high voice quality: if a VOIP system can't deliver similar quality, they will try it a few times and then abandon it in favour of the tried and trusted public telephony system. If this happens, all your expensive investment will be wasted; and, as companies that have been burned by poor IVR implementations have learned, it's very hard to convince users or customers to give a new technology a second chance if their first experience is poor.

A pilot project will give you the opportunity to assess user reaction and to decide what may need to be added or changed before you opt for a full-scale roll-out to a large user base. A properly designed, user-centred VOIP system with the appropriate backend systems should have no trouble in finding acceptance.