PortSIP Softphone 16.0

This is a full featured Voice Over IP Phone in software used to connect with VoIP PBX compatible with SIP like Open SER, Asterisk, Portaone, Radvision, Nortel, or a variety of international telephony providers.

It has a lot of popular features like call recording, attended and blind transfer, hold, auto answer, do not disturb, and conference with a maximum of 5 parties.

This application allows audio and video calls, with the codecs: G.711 aLaw/uLaw, GSM, iLBC, G723.1, G729, H263, H263-1998, H264.

It has multiple lines, a phonebook and a recent calls log.

It offers support for Windows 2000/XP/2003/Vista, Windows Mobile 5/6, Nokia S60 3rd FP2.

This program is free to download, but there are commercial packages for enterprises that offer private labeling and skins, importing contacts from Outlook, and others.

A downside to this program is its design, its graphics are quite basic and need a lot of work, but I would definitely recommend it if you need a free telephone to test an Asterisk implementation.