tokens: ['IMSSF', '', '', 'native', 'IMS', 'application', 'server', 'OSASCS', 'an', 'Open', 'Service', 'Access', '', 'Service', 'Capability', 'Server', 'interfaces', 'with', 'OSA', 'Application', 'Servers', 'using', 'Parlay', 'IMSSF', 'an', 'IP', 'Multimedia', 'Service', 'Switching', 'Function', 'interfaces', 'with', 'CAMEL', 'Application', 'Servers', 'using', 'CAP', 'The', 'architecture', 'is', 'based', 'on', 'the', 'principle', 'that', 'the', 'service', 'control', 'for', 'Home', 'subscribed', 'services', 'for', 'a', 'roaming', 'subscriber', 'is', 'in', 'the', 'Home', 'network', 'eg', 'the', 'ServingCSCF', 'is', 'located', 'in', 'the', 'Home', 'network', 'There', 'are', 'two', 'possible', 'scenarios', 'to', 'provide', 'services', 'see', 'figure', '', 'via', 'the', 'service', 'platform', 'in', 'the', 'Home', 'Network']