When you install SIP Communicator, you will probably find it will run successfully, initializing an appropriate internal copy of JMF and using its default configuration file. The setup wizard will prompt you for some basic parameters for your sip user account.
FIXME: add specific tips like “how to disable STUN”, “how to use IPv6″, “how to disable Proxy and Registrar” and so.
See Resetting the SIP Communicator Configuration for a description of how to get SIP Communicator to re-detect its configuration when you make an important change.