KPhone is a SIP User Agent for Linux. It implements the functionallity of a VoIP Softphone but is not restricted to this. It is licensed under the GNU General Public License. KPhone is written in C++ and uses the Qt toolkit.

KPhone establishes Sessions via the Internet and so enables communication between the endpoints. Audio is the "session type" used most frequently, but others are possible .

KPhone supports as well SIP Proxy Agents as direct communication between User Agents. The latter may be not possible if firewalls and NATs restrict point-to-point communication.

The main features:
  • IPv4 and IPv6 support
  • Multiple parallel sessions (in the case of audio, one may be active, the others are held).
  • user defined ring tones or "ring music"
  • NAT-traversal and STUN support
  • ALSA and OSS support
  • SRTP encryption for voice (not yet for 64bit processors)
  • Call Hold
  • Call Transfer
  • Call Forwarding
  • Auto Answer

The following media types are supported:
  • Audio
  • presence information
  • instant messaging
  • video (with the external application vic)
  • External Applications

For the external applications the user manual discusses the supported formats and how to install an external application. A good example is KPhoneIM, a simple point-to-point IM application, other examples are the MICE Tools of the project MBONE such as vic and wbd (whiteboard). (As they do not support symmetric signalling, NAT-Traversal is not possible with these tools).
KPhone itself supports STUN for NAT traversal. It may be used for the buildin audio solution and for KPhoneIM immediately, other external applications may need some adaption to make use of it. (See the user manual of KPhoneSI and of KphoneIM for more). The MBONE-Tools - as vic, kphone-vic and wbd - do not support NAT-traversal yet!

Home of the Project:


Up to summer '05 KPhone's home was here:

The first IPv6 implementation can be found here:

Fedora RPMs (up to kphone 4.1)

Debian's Packages (kphone 4.2)

Short Review

Asterisk Configuration for KPhone
Created by: admin, Last modification: Sun 17 of Aug, 2008 (10:21 UTC) by kgfleischmann
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