Twinkle is one the best free open source softphone for Linux. This free softphone supports voice over IP (Voip) and instant messaging using SIP protocol and could be used for direct IP phone to IP phone communications.
Free VOIP Softphone – Twinkle
Twinkle offers a simple and user friendly interface. Being a popular SIP program, it’s already present in most of the linux repositories available. This Voip application uses Qt toolkit for its graphical UI and is one of the extremely powerful and handy SIP client. Also checkout my previous post on free voip softphone.
On Ubuntu or Debian, you just have to use the following command:
#apt-get install twinkle
Launch the softphone:
Features of Twinkle Softphone
- Multiple active call identities
- Custom ring tones
- Call Waiting
- Call Hold
- 3-way conference calling
- Inband DTMF
- Out-of-band DTMF
- STUN support for NAT traversal Call redirection unconditional
- Call redirection when busy
- Call redirection no answer
- Reject call redirection request
- Blind call transfer
Audio drivers aupported by twinkle : Open Sound System (OSS) ,Advanced Linux Sound Architecture (ALSA).
Disadvantages of twinkle being NO video support, call recording and IM emoticons.