DUM Common Errors

From reSIProcate

• Creating then Sending Messages without Message References (do not copy messages returned from the makeXXXX api's)
• Calling DUM API's from mulitple threads (without syncronization) - see Threading section for more info
• Calling InviteSession::end() and expecting CANCEL to be sent - see Ending Invite Sessions section for more info.
• Forgetting to call select on the FDSet, before calling process