In addition, VOIP phones only transmit sound when you are actually speaking into the mouthpiece, further reducing the bandwidth necessary for voice communication.

Another reason that telecommunications companies are so excited about VOIP technology is that it saves them the burden of maintaining two separate communications networks. If telephone calls were placed digitally over data networks such as the Internet, telecommunications companies (including UIS) would have to maintain and upgrade a single network instead of two.

By making phone use more efficient, VOIP technology could reduce the cost of phone use for telecommunications companies and consumers.

The flip side of using data networks for phone calls is that data networks are typically far less reliable than their telephone counterparts, which reserve a set amount of bandwidth for each telephone conversation.

Normal telephone calls are almost always completed and do not become disjointed because of a surge in traffic over the telephone network.

However, if Harvard's data network slows suddenly while a student is downloading a website, the student simply has to wait an extra second or two for the page to load. If the same were to happen during a telephone call, some part of the conversation would not get through or would be delayed to such an extent that normal conversation would be difficult. In fact, studies have found that delays of more than a half a second in voice conversations would render VOIP essentially useless.

The main problem with VOIP so far, says Donnelly, is that it doesn't handle sudden bursts of traffic over the network very well. If your roommate were to begin downloading a large file while you were talking on the phone, your conversation might begin to break up.