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.
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/1.8.10 pjproject
$ cd pjproject
Create the file pjlib/include/pj/config_site.h with the following
contents.
#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"
Configure and build Telephone
$ ./configure --disable-ssl
$ make
Telephone source code follows Google Objective-C Style Guide.