tokens: ['registraton', 'on', 'behalf', 'of', 'the', 'WebRTC', 'client', 'The', 'details', 'of', 'the', 'signalling', 'flows', 'are', 'as', 'follows', 'NOTE', '', 'If', 'the', 'WAF', 'resides', 'in', 'the', 'operator', 'domain', 'we', 'can', 'use', 'the', 'WAF', 'control', 'to', 'authorize', 'the', 'WWSF', 'If', 'WAF', 'is', 'not', 'in', 'the', 'operator', 'domain', 'then', 'we', 'can', 'use', 'the', 'authorization', 'of', 'the', 'WWSF', 'by', 'SCSCF', 'and', 'HSS', '', 'Token', 'request', 'WWSF', 'to', 'WAF', 'If', 'the', 'WAF', 'resides', 'in', 'the', 'operator', 'domain', 'when', 'the', 'WAF', 'receives', 'a', 'token', 'request', 'it', 'can', 'either', 'authenticate', 'the', 'user', 'itself', 'as', 'part', 'of', 'the', 'token', 'issuance', 'process', 'or', 'it', 'trusts', 'the', 'user', 'identity', 'supplied', 'by', 'the', 'WWSF', 'which', 'is', 'assumed', 'to', 'have', 'authenticated', 'the', 'user', 'prior', 'to', 'sending', 'the', 'token', 'request', 'Only', 'if', 'this', 'check', 'is', 'successful', 'will', 'the', 'WAF', 'return', 'the', 'authorization', 'token', 'otherwise', 'the', 'WAF', 'rejects', 'the', 'request', 'of', 'the', 'WWSF', 'And', 'if', 'a', 'WWSF', 'is', 'suspected', 'of', 'a', 'security', 'breach', 'the', 'WAF', 'will', 'block', 'all', 'token', 'requests', 'originating', 'from', 'that', 'WWSF', '', 'REGISTER', 'request', 'WebRTC', 'IMS', 'Client', 'to', 'Trusted', 'Node', 'The', 'WebRTC', 'IMS', 'Client', 'establishes', 'a', 'secure', 'WebSocket', 'connection', 'with']