Cisco's CEO John Chambers predicts that enterprise networks will accelerate their adoption of Voice over IP technology.
There are currently several problems with this technology. If the computer or network lines fail, then telephone service is interrupted. While the stability of computer hardware, operating systems and network infrastructure has improved significantly in the last decade, crashes still occur. The "up" time of these systems is still significantly less than with traditional phone systems--which often continue to function even during power outages. Another issue is that tracking the origin of a call is difficult because the signals are transmitted over the Internet. This is especially important to emergency responders to 911 calls. Caller ID service may not function either. Additionally, devices that make calls using phone lines, such as fax machines, cable TV boxes, etc. may not function properly. Law enforcement officials may have difficulty wiretapping phone lines that use VoIP technology. Finally, the quality of VoIP service is lower than that of a traditional phone system. Since the information is transmitted over network lines, it is subject to the same issues that other data streams experience including delays, packet loss and bandwidth availability. Thus VoIP phone calls may break up, hesitate, or cause words to be dropped. All of these issues are being addressed and their significance should be eliminated over time.