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  • John Bell

Tech Sense: Phones part 2

Phones Part 2

This month, we continue our discussion of telephones. We ended last month discussing how Internet phone companies provide the bridge between Voice over Internet Protocol (VoIP) and the public switched telephone network (PSTN). Internet phones often use the Session Initiation Protocol (SIP) to make telephone connections between Internet phones. An Internet phone can be a dedicated VoIP device, or it can be an application that runs on your computer, mobile phone, or tablet. It requires a microphone and speakers to use your computer. These applications are often called “softphones” because they are implemented in software. Most modern Android phones include a built-in softphone that can be enabled through the setup application. Search the setup app for “Wi-Fi calling.” As we discussed last month, an old-fashioned phone device is usable with an analog telephone adapter (ATA).

Google Voice

Last month, we discussed VoIP providers and incoming phone numbers, or DID's. If you are going through most VoIP providers, there is a fee for the DID and for the service to connect to the PSTN. Google has offered a service for many years now known as Google Voice. Google Voice gives you an incoming phone number for free to use with its service, which is also free. You can port your existing phone number over for a small fee (about $20). Google Voice provides a number of phone services including voicemail, call forwarding, and a feature that rings all of the phones that you list with them. Google Voice can also block spam phone calls. The voice mail messages left on Google Voice can be picked up on your mobile phone or computer, so you never have to miss another answering machine message. Phone calls in the USA are free, and international calls are very inexpensive (about 2 cents per minute to Europe, for example).


A private branch exchange, or PBX, is used for businesses where they need multiple internal phone lines that can interconnect. A PBX allows phones to be used for interoffice calling and outside calling and allows many phones to share a small number of outgoing lines. Not too long ago, it was common for a PBX to be implemented as specialized hardware that was installed into each business location. Today, this can be done with software on a personal computer, or even a small $30 computer like the Raspberry Pi. Asterisk is a popular free and open source program that provides full PBX functionality and runs on many computers including the Pi. The latest trend is to host the PBX in the cloud. There is no longer a need to install any hardware in the office other than the VoIP phones or ATA. The PBX can span offices that are located far apart in different cities, states, and even countries.

SIP to SIP Calling

If you already have Internet, you can make free phone calls using VoIP and SIP without ever connecting to the PSTN. Most softphones support this feature and will accept incoming calls directly from other SIP-based VoIP phones. Because there is no PSTN connection involved, these Internet phone calls are free anyplace in the world.

Skype and Other Ways to Talk

Of course, there are alternatives. Most people have heard of or used Skype, which is now owned by Microsoft. Skype allows both voice and video chat, and the business version now supports SIP and supports some VoIP phones. Skype users can talk to any other Skype user in the world free. Skype can also bridge to the regular PSTN to make ordinary phones call for a small per-minute fee that varies from country to country. The Skype app is available on most computers and modern mobile phones. Google provides Hangouts, which, like Skype, works on most computers and mobile phones and allows calling landlines for a small fee.

As an alternative to Skype, Apple offers the FaceTime app, and Google offers both Hangouts and the Duo app. While these are intended as Skype alternatives, neither FaceTime nor Duo can connect to regular landline phones or support SIP and other VoIP protocols. Therefore, FaceTime and Duo are not phone applications; instead, we call these video chat applications. Both Skype and Hangouts can interact with VoIP and PSTN phones and behave as true phone applications.

Also, FaceTime is only available for Apple phones and devices and only allows video chatting with other Apple devices running FaceTime. Sorry if you want to call someone with an Android phone. Google's Duo is similar to FaceTime, designed to support secure, high definition (HD) video chat over low bandwidth networks. Like FaceTime, Duo can only talk to other phones with Duo and cannot connect to regular phones lines. Unlike FaceTime, Duo is available on both Android phones and iPhones.

Wrap Up

I have tried to give a quick overview of some of the changes the Internet has brought to the telephone. Obviously, there is a lot that I have left out. Hopefully, I have given you things to search for and read on the Internet. Next month, I will cover potential technology gifts for the holidays. In the meantime, reach out and call someone from your computer.

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