Softphone is a software telephone. It is a software program for making telephone calls over the Internet. Calls go through the Internet or through any IP network.
Install the software phone on any device: computer, laptop, netbook or smartphone to receive and make calls through the Internet.
You won't need any additional hardware except the microphone and headphones or speakers to make voice or video calls. And for video calls you'll need a camera of course. That means you can just perfom calls with your mobile phone since it has all the necessary attributes.
Most of softphones also include chat and video conferencing functions, calls forwarding and SMS.
We suggest you to use the popular softphones for communication through Excel: