Many people have made the switch to internet based telephony services (VOIP) for both business and personal use. These services are great for everyday use but during a disaster or emergency situations they do have some drawbacks.
Though VOIP has some positives as well, none of these will be beneficial during a time of crisis, and the two biggest drawbacks of VOIP is that it is dependant on the internet being operational, and requires a separate working power source.
More people are using only cell phones, that are also dependant on cellular towers working, and the limitations of the technology.
Land-line based phone systems are not susceptible to these drawbacks and is still one of the best ways to stay in contact with people. Land-line phones systems also carry their own electrical current to power the communications systems.
If you do not currently have a land-line phone, I would highly suggest that you get one. You can typically call your phone company and tell them that you plan on maintaining the system just for emergencies and they will provide the service for a nominal fee.