What are hardphones?

Hardphones (also known as VoIP or IP phones) are purpose-built hardware devices that look much like an ordinary telephone, but use VoIP protocols instead of the traditional public switched telephone network (PSTN) to establish and transmit phone calls. Today, hardphones have largely replaced analog phones in corporate environments. They offer features that are usually not available on ordinary telephones, such as the voicemail forwarding to an email, sharing of contact lists, call recording, etc.

Hardphones look really similar to analog phones. Here is a picture of a phone we will be using in this course:

The phone pictured above is Yealink SIP T20P. Just like an analog telephone, SIP T20P has a handset, a keypad to enter phone numbers, a screen that shows information about calls, a volume key to adjusts the volume of the handset, LEDs to indicate phone status, and such. Here is the same phone from the back side:

On the back side are the power port and two Ethernet ports – the Internet port and the PC port. These two ports act as a switch – you connect the phone to your network using the Internet ports, and then you can connect additional device (e.g.) your PC to the PC port on the telephone.