tSIP - free and with BSD license. Obviously feature list would not be identical to yealink and other desk phones, some functions are missing (e.g. built-in conference, must be done server-side with feature codes) but on the other hand Lua scripts can be assigned to buttons or run on events.

@bigbear said in Need a full featured softphone:

Call disconnected when other extension picked up.

Sounds like no audio device present (e.g. sound card with autosensing but no microphone connected) then. Unless there is some late negotiation involved with direct rtp setup and no common codecs.

However it looks promising and is open source. I only messed with it for a few minutes.

See also https://github.com/alfredh/baresip

@bigbear See http://tomeko.net/software/SIPclient/howto/troubleshooting.php. One odd problem I know of is that if multiple network network interfaces are present on the machine and virtual interface is present and configured with higher priority it may require binding to "proper" interface through Settings/Network - either by IP or interface GUID as printed in log.
Other than that, you may need to register first (setting Register Expires to non-zero and other account stuff) and calling requires audio input device which may be not present if mic is not connected. Either log of wireshark should contain some clues for other problems (SIP/488, SIP/403, etc.).

tSIP - free and with BSD license. Obviously feature list would not be identical to yealink and other desk phones, some functions are missing (e.g. built-in conference, must be done server-side with feature codes) but on the other hand Lua scripts can be assigned to buttons or run on events.