Ekiga

Ekiga is an H.323 compatible videoconferencing and VOIP/IP-Telephony application that allows you to make audio and video calls to remote users with H.323 hardware or software (such as Microsoft Netmeeting). It supports all modern videoconferencing features, such as registering to an ILS directory, gatekeeper support, making multi-user conference calls using an external MCU, using modern Quicknet telephony cards, and making PC-To-Phone calls.


Twinkle

Twinkle is a soft phone for VoIP communcations using the SIP protocol. You can use Twinkle for direct IP phone to IP phone communications or in a network using a SIP proxy to route your calls.

In addition to making basic voice calls, Twinkle also provides the following features:

* 2 call appearances (lines)
* Multiple active call identities
* Custom ring tones
* Call Waiting
* Call Hold
* 3-way conference calling
* Mute
* Call redirection on demand
* Call redirection unconditional
* Call redirection when busy
* Call redirection no answer
* Reject call redirection request
* Blind call transfer
* Reject call transfer request
* Call reject
* Repeat last call
* Do not disturb
* Auto answer
* User defineable scripts triggered on call events
* E.g. to implement selective call reject or distinctive ringing
* RFC 2833 DTMF events
* Inband DTMF
* Out-of-band DTMF (SIP INFO)
* STUN support for NAT traversal
* Send NAT keep alive packets when using STUN
* NAT traversal through static provisioning
* Missed call indication
* History of call detail records for incoming, outgoing, successful and missed calls
* DNS SRV support
* Automatic failover to an alternate server if a server is unavailable
* Other programs can originate a SIP call via Twinkle, e.g. call from address book
* System tray icon
* System tray menu to quickly originate and answer calls while Twinkle stays hidden
* User defineable number conversion rules