So, is it worth the investment? The answer is, as usual, "it depends." VoIP is evolutionary, not revolutionary, technology. If you are moving into a facility where you need to completely build out your infrastructure, then installing VoIP equipment makes sense. It can be very competitive with traditional POTS switched networks. Some companies put a VoIP blade in an existing POTS switch. They feel that it gives them the best of both worlds, but I suspect that they might be hedging their bets a bit too much and not benefiting fully from either technology.
There are some other ways that you can take advantage of VoIP technology. In a "green field" installation, you have a number of attractive choices that can give you more network flexibility. One possibility is eliminating the wires entirely. There is nothing preventing you from installing VoIP over wireless 802.11x networks. "The security algorithms do introduce some latency, but because of the short distances they shouldn't be a problem," says Tyliszcak.
Unified messaging is another example. Unified messaging is one-stop shopping for all your voice mail, email, and fax communications. Unified messaging lets you retrieve all your messages with one phone call or visit to a website. While unified messaging sounds great, the technology has not entirely jelled yet. It can be costly and complicated to implement, and the services have not been perfected, including problems with voice to text translation. Unified messaging is dependent on the VoIP technology so as that application matures, there will be more incentive to implement a VoIP solution.
Recently, Cisco has been investing heavily in VoIP for the enterprise market. They are sponsoring a major trial with the city of Houston, TX and are replacing the entire municipal government telecom service with Cisco VoIP equipment. They claim that it will save 50% over the costs of maintaining the old equipment.
Of course, it isn't clear whether or not replacing Houston's old system with a more modern switched network would result in similar savings. As Chris Ward, notes, "Enterprises' IT departments are real pragmatists. They will not invest in a technology unless there are demonstrated cost savings or substantial improvements in the quality of service."
Here's a checklist of things to watch for when considering whether to invest in VoIP: