Telephone is a VoIP program which allows you to make phone calls over the internet. It can be used to call regular phones via any appropriate SIP provider. If your office or home phone works via SIP, you can use that phone number on your Mac anywhere you have decent internet connection.

Building

Telephone's SIP user agent is based on pjsip. You need to build it before building Telephone. Name the directory pjproject and place it near Telephone, in the same parent directory.

$ svn checkout http://svn.pjsip.org/repos/pjproject/tags/2.4.5 pjproject
$ cd pjproject

Create the file pjlib/include/pj/config_site.h with the following contents:

#define PJMEDIA_AUDIO_DEV_HAS_PORTAUDIO 0
#define PJMEDIA_AUDIO_DEV_HAS_COREAUDIO 1
#define PJSIP_DONT_SWITCH_TO_TCP 1
#define PJSUA_MAX_ACC 32
#define PJMEDIA_RTP_PT_TELEPHONE_EVENTS 101
#define PJMEDIA_RTP_PT_TELEPHONE_EVENTS_STR "101"
#define PJ_DNS_MAX_IP_IN_A_REC 32
#define PJ_DNS_SRV_MAX_ADDR 32
#define PJSIP_MAX_RESOLVED_ADDRESSES 32

Configure and build pjsip:

$ CFLAGS="-mmacosx-version-min=10.9" ./configure
$ make lib

Build Telephone.