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• CCITT Rec. U.15 (11/1988) – INTERWORKING RULES FOR INTERNATIONAL SIGNALLING SYSTEMS ACCORDING TO RECOMMENDATIONS U.1, U.11 AND U.12
• 1 General
• 2 Rules for alternative routing
• 3 Rules for conversion of TCICs and NICs (see Table 1/U.15 for details)
• 4 A third COT on type D to allow conversion of NIC to TCIC, and overcome possible call connected signal and ...
• 5 Rules for service signal conversion
• 6 Rules for exchange of line identifications
• 7 Rules for call connected signal conversion
• 8 Rules for obtaining the called subscriber's answerback when interworking type D with other signalling systems