1.     Loss of service during power outages.  Without power VOIP phones are useless. During a blackout a regular phone is kept in service by the current supplied through the phone line. This is not possible with Internet phones, so when the power goes out, there is no VoIP phone service. One solution to this problem is to use battery backups or power generators to provide electricity. This downside is also mitigated if you have a cell phone.

2.     With VOIP emergency calls, it is hard to locate you and send help in time. Traditional phone equipment can trace your location. Emergency calls are diverted to the nearest call center where the operator can see your location in case you can't talk. With VoIP, however, there is currently no way to determine where your Internet phone call is originating from, so most VoIP services cannot be used for emergency calls. There is an emerging standard called e911, however, which attempts to address this issue.

3.     Quality and Reliability. Because VOIP relies on an Internet connection, your VOIP service will be affected by the quality and reliability of your broadband Internet service and sometimes by the limitations of your PC. Poor Internet connections and congestion can result in garbled or distorted voice quality. If you are using your computer at the same time as making a computer VOIP call, you may find that voice quality deteriorates dramatically.

4.     Latency and traffic. The amount of data that is lost depends on the distance and speed of the connection. Some networks receive a lot of traffic and are more likely to cause dropouts in the audio stream. Creating dedicated data paths is one way to provide high quality audio connections.

The disadvantages of VOIP could be annoying, but their effects are relatively limited. The complaints of VOIP are usually tolerable if the callers are using a cheap phone service. As the technology is advancing, we will expect the VOIP quality will match the traditional telephone technology. Here are the advantages of VOIP.