Isdn Pbx Sip Telephony shareware, demo, freeware, software downloads, downloadable, downloading

PC-Telephone

... (SoftPhone) capable to provide telecommunications services such as telephony and file/fax transfer on various communications networks – ... It turns the computer into an Internet/VoIP telephone, ISDN telephone, fax machine, voicemail, VoIP switch/PBX and more. ...