Although VOIP has many great advantages, you should be aware of following downsides as well.

Power Interruptions

With your traditional phone line, if power goes out, you can still pick up your phone to call.

With VoIP, if the power goes out then there is nothing to power your internet connection or your VoIP phone. One solution to this problem is to use battery backups or power generators to keep you VoIP service powered.

Emergency 911 calls

With your traditional phone, 911 calls is quickly traced to its origin and routed to the nearest call center where the operator will be able to see your location. But with VoIP, voice packets will be transfer over IP networks and so it is not possible to determine where a VoIP call is originating from.

To solve this problem, there is an emerging standard known as “e911”. Your VoIP service providers pass name and address information to the nearest Public Safety Access Point (PSAP) when 911 is dialed. As not all PSAPs in the country support E911 yet, so you should ask when deciding on a VOIP service provider, if E911 is supported in your area.

Reliability

As VoIP uses high speed internet connection to transmit voice traffic over IP-based networks, your VoIP call will be affected by the quality and reliability of your broadband Internet service. Poor Internet connections and congestion can result in distorted voice quality.

Bad or unreliable internet connections can result in poor voice quality, such as clipping, voice delay, or dropped calls.