Ekiga is a SIP and H.323 application, supporting audio and video, and is the successor of GnomeMeeting.

Here are some key features of "Ekiga":

· Call Forwarding on busy, no answer, always (SIP and H.323)
· Call Transfer (SIP and H.323)
· Call Hold (SIP and H.323)
· DTMFs support (SIP and H.323)
· Basic Instant Messaging (SIP)
· Text Chat (SIP and H.323)
· Possibility to register to several registrars (SIP) and gatekeepers (H.323)
· Possibility to use an outbound proxy (SIP) or a gateway (H.323)
· Message Waiting Indications (SIP)
· Audio AND Video (SIP and H.323)
· STUN support (SIP and H.323)
· DTMFs support
· LDAP support