Twinkle is a free and open-source app for voice communications over

Voice over IP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet t ...

(VoIP) protocol. It is designed for

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...

operating systems and uses the Qt toolkit for its graphical user interface. For call signaling it employs the Session Initiation Protocol (SIP). It also features direct IP-to-IP calls. Media streams are transmitted via the

Real-time Transport Protocol The Real-time Transport Protocol (RTP) is a network protocol for delivering audio and video over IP networks. RTP is used in communication and entertainment systems that involve streaming media, such as telephony, video teleconference applicati ...

(RTP) which may be encrypted with the

Secure Real-time Transport Protocol The Secure Real-time Transport Protocol (SRTP) is a profile for Real-time Transport Protocol (RTP) intended to provide encryption, message authentication and integrity, and replay attack protection to the RTP data in both unicast and multicas ...

(SRTP) and the

ZRTP ZRTP (composed of Z and Real-time Transport Protocol) is a cryptographic key-agreement protocol to negotiate the keys for encryption between two end points in a Voice over IP (VoIP) phone telephony call based on the Real-time Transport Protocol. ...

security protocols. Since version 1.3.2 (September 2008), Twinkle supports message exchange and a ''buddy-list'' feature for presence notification, showing the online-status of predefined communications partners (provider-support needed).

Supported audio formats

G.711 G.711 is a narrowband audio codec originally designed for use in telephony that provides toll-quality audio at 64 kbit/s. G.711 passes audio signals in the range of 300–3400 Hz and samples them at the rate of 8,000 samples per second ...

A-law: 64 kbit/s payload, 8 kHz sampling rate * G.711 μ-law: 64 kbit/s payload, 8 kHz sampling rate *

G.726 G.726 is an ITU-T ADPCM speech codec standard covering the transmission of voice at rates of 16, 24, 32, and 40 kbit/s. It was introduced to supersede both G.721, which covered ADPCM at 32 kbit/s, and G.723, which described ADPCM for ...

: 16, 24, 32 or 40 kbit/s payload, 8 kHz sampling rate *

GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...

: 13 kbit/s payload, 8 kHz sampling rate *

G.729 G.729 is a royalty-free narrow-band vocoder-based audio data compression algorithm using a frame length of 10 milliseconds. It is officially described as ''Coding of speech at 8 kbit/s using code-excited linear prediction'' speech coding (CS-ACEL ...

: 8 kbit/s payload, 8 kHz sampling rate *

iLBC Internet Low Bitrate Codec (iLBC) is a royalty-free narrowband speech audio coding format and an open-source reference implementation (codec), developed by Global IP Solutions (GIPS) formerly Global IP Sound (acquired by Google Inc in 2011). ...

: 13.3 or 15.2 kbit/s payload, 8 kHz sampling rate *

Speex Speex is an audio compression codec specifically tuned for the reproduction of human speech and also a free software speech codec that may be used on VoIP applications and podcasts. It is based on the CELP speech coding algorithm.Xiph.OrIntro ...

narrow band: 15.2 kbit/s payload, 8 kHz sampling rate * Speex wide band: 28 kbit/s payload, 16 kHz sampling rate * Speex ultra wide band: 36 kbit/s payload, 32 kHz sampling rate

References

Free VoIP software Cryptographic software Internet privacy software Secure communication Software that uses Qt KDE software {{network-software-stub

Supported audio formats

See also

References