In general, VoIP is a substantial improvement over traditional landline services, but there are few obvious downsides to VoIP.
It’s more reliable. While the PTSN has little redundancy and calls can be lost or incomplete if there are network issues, VoIP uses the internet, which is robust and can routinely work around outages and hardware problems.
VoIP can be significantly cheaper than landlines. Businesses like VoIP because it requires substantially less hardware to connect a large number of phones to the PTSN. Residential users can often get VoIP bundled with internet and cable TV for less money than a landline from a traditional phone provider would cost.
It’s mobile. Because IP phones are simply internet devices, you can typically move an IP phone to any available Ethernet connection ó it’s not restricted to a specific desk or location. Even better, a VoIP user can generally use a compatible VoIP app on their phone to make calls when away from the VoIP phone.
You generally need a broadband internet connection. You don’t need a lot of bandwidth for voice communication, but if your internet connection is below about 10Mbps, you can have problems with audio quality.
Internet connectivity issues can disrupt phone service. As a general rule, VoIP is highly reliable. But if you do have an internet connectivity problem, it can take out both data and voice at the same time. If you had a landline, it would probably not have been affected by the internet outage.
You might have issues with 911 services. The FCC requires that VoIP provider who fully connect to the PTSN provide emergency 911 services. But there are exceptions ó not all VoIP systems need to be compatible with Enhanced 911 services ó and there might be situations when a call to 911 does not automatically provide emergency services with your location.