e/Call completion

Information
has gloss	eng: Call Completion is a telephony feature allowing some form of alternative interaction between parties who cannot converse directly with each other. There are several possible factors which can prevent a call from connecting successfully: * User does not answer * User is busy in another call * User is offline/unavailable * User actively disconnects the call before answering
lexicalization	eng: Call completion
instance of	c/Calling features