st> transport := SIPUdpTransport startOn: '172.16.254.33'.
st> useragent := SIPUserAgent createOn: transport.
st> transport start.

"Create a call"
st> sdpfile := nil.
st> call := SIPCall fromUser: 'sip:1000@on-waves.com' host: '172.16.1.72' port: 5060 to: 'sip:9198@172.16.1.72' on: useragent
st> call createCall: sdpfile.
st> stdin next

"Try to hangup an active call"
st> call hangup

"Try to cancel a non active call"
st> call cancel

"Try to terminate either by hangup or by cancel"
st> call terminate