Where can I get a SIP account?
You can get a SIP account from a SIP provider. SIP provider is a phone provider that allows making calls via the SIP protocol. Chances are, your current phone provider already does that. If not, just search the internet for a SIP provider in your location. The local phone providers often have lower prices or special offers for local calls. But you're not restricted to a local provider. In general, any SIP provider should work.
How to enable debug information
Run Telephone using this command in Terminal:
/Applications/Telephone.app/Contents/MacOS/Telephone -LogLevel 4
If you prefer to save the debug information and start the app normally, set it in preferences with this command:
defaults write com.tlphn.Telephone LogLevel -integer 4
To reset the log level:
defaults delete com.tlphn.Telephone LogLevel
Where is the log file?
The log file can be revealed in Finder from the main menu: Help > Show Log File in Finder.
The log file is overwritten every time Telephone starts.
How to make calls from macOS Contacts?
In FaceTime preferences, check the checkbox Calls from iPhone and set Telephone as Default for calls. Now it should be possible to make calls from the Contacts app by clicking a phone icon. The phone icon usually appears below the contact name. It is also shown next to a phone number when the mouse cursor is over it.
How to make calls from the Contacts app on macOS High Sierra or earlier?
You need to manually install Contacts app plug-ins. Unpack them and copy the two .bundle files into the folder /Users/<username>/Library/Address Book Plug-Ins. Restart the Contacts app if needed. Now, when you click a label like ‘home’ or ‘work’ next to a phone number, the context menu that appears will have the Dial with Telephone item.
By default, the user’s Library folder is not shown in Finder. To navigate to it, open Finder, press Command-Shift-G shortcut or select Go > Go to Folder... in the main menu. Paste ~/Library in the appeared text field and click Go.
If there is no Address Book Plug-Ins folder inside Library, simply create it.
I have sound problems with FritzBox
Try to enable “Use only G.711 codec” in Telephone sound preferences.
I hear echo
An echo occurs when sound from speakers is captured by the microphone. The cause of the echo is usually on another end of the conversation. If you hear echo, please ask another party to use a headset or headphones.
Another party hears echo
As in the previous question, using a headset or headphones should help. In this case, however, the cause of the echo is on your side.
Which headset can be recommended?
Even simple headsets that come with mobile phones can significantly increase the sound quality and reduce echo. A bluetooth headset can be a convenient but not the most reliable choice. The bluetooth paring problems in the OS are still not uncommon. The most reliable choice would be a higher quality USB headset. Plantronics .Audio 400 DSP is an example of a decent portable USB headset.
How to send tone signals
Just press digits on the keyboard when the call window is active. Asterisk (*) and number sign (#) are also allowed. The character R represents a DTMF flash, which needs to be supported by the other side.
Why sending tone signals doesn’t work?
When calling regular phones, sending tone signals must be supported by the VoIP gateway. If the gateway does not support RFC 2833 or SIP INFO DTMF standards, the signals will not be sent.
How to place a call on hold
Press H in the active call window.
How to mute the microphone during a call
Press M in the active call window.
How to create sip: and tel: links
Please note that there are no slashes after the URI scheme.
To set Telephone as default tel URLs handler in macOS, select it as Default for calls in FaceTime preferences.
How to make calls from a text selection in another application
You need to enable Telephone: Call in macOS Services. Go to System Preferences > Keyboard > Shortcuts > Services > Text. Check Telephone: Call and optionally add a keyboard shortcut. Now, if you select a text in another application and right-click on it, there should be Telephone: Call in the appeared context menu. If you click it, Telephone should use the selected text as a call destination. It is possible to use the assigned keyboard shortcut instead of clicking.
Where can I store SIP addresses?
You can save SIP addresses (email@example.com) in macOS Contacts app as an email with a custom label sip. Telephone autocompletes such addresses and Contacts app plug-in shows Dial with Telephone for them. The Contacts app plug-ins are supported only on macOS High Sierra or earlier.
Which codecs are supported?
Speex/8000 (narrowband), Speex/16000 (wideband), and Speex/32000 (ultra-wideband)
G.711 (PCMA, PCMU)
L16 family of codecs