tokens: ['Figure', '', 'shows', 'the', 'Diameter', 'transactions', 'that', 'are', 'required', 'between', 'AS', 'implementing', 'the', 'CUG', 'service', 'and', 'CDF', 'for', 'a', 'successful', 'originating', 'communication', 'from', 'UserA', 'CUG', 'member', 'Figure', '', 'Message', 'sequence', 'chart', 'for', 'offline', 'charging', 'of', 'CUG', 'service', '', 'originating', 'call', 'UserA', 'is', 'subscribed', 'to', 'CUG', 'service', 'and', 'initiates', 'a', 'communication', 'towards', 'User', 'B', '', 'UserA', 'initiates', 'a', 'communication', 'towards', 'User', 'B', 'sending', 'SIP', 'INVITE', 'request', 'Based', 'on', 'the', 'Initial', 'Filter', 'Criteria', 'IFC', 'rules', 'indicating', 'that', 'User', 'A', 'is', 'subscribed', 'to', 'the', 'CUG', 'supplementary', 'service', 'the', 'communication', 'is', 'forwarded', 'to', 'an', 'AS', 'implementing', 'CUG', '', 'AS', 'performs', 'checks', 'from', 'the', 'request', 'received', 'regarding', 'User', 'A', 'CUG', 'subscription', 'profile', 'and', 'determines', 'the', 'CUGcommunication', 'is', 'allowed', 'for', 'CUG', 'member', 'UserA', 'towards', 'UserB', '', 'AS', 'forwards', 'SIP', 'INVITE', 'towards', 'UserB', 'with', 'CUG', 'information', 'included', 'NOTE', 'In', 'case', 'the', 'result', 'from', 'AS', 'checks', 'indicates', 'nonCUG', 'communication', 'behaviour', 'for', 'CUG', 'communication', 'with', 'outgoing']