Binary package “twinkle” in ubuntu bionic

Voice over Internet Protocol (VoIP) SIP Phone (GUI)

 Twinkle is a soft-phone for making telephone calls over an IP network
 using the SIP protocol. You can use it for direct IP phone to IP phone
 communication or in a network using a SIP proxy to route your calls.
 Notable features include multiple active identities, call transfer,
 call rejection, 2 simultaneous calls and 3-way conference calls.
 .
 This package contains the graphical interface.