Download

292 ISDN USER PARTPar.14 Forward Call Indicators. This is a mandatory (MF) parameter in IAMmessages (Fig. 11.2-5). It contains indicator bits with information for the intermediateand terminating exchanges in a connection.BitsBitsA Call type CB End-to-end signaling0 Call to be treated as national call 00 Not available1 Call to be treated as international call 01 Pass-along method available10 SCCP method available11 Pass-along and SCCPmethods availableD Interworking indicator0 No interworking encountered (TUP orISUP signaling all the way)1 Interworking encounteredF ISUP indicator HG ISUP preference indicator0 ISUP signaling not used all the way1 ISUP signaling used all the wayI ISDN access indicator0 Calling party has non-ISDN access(analog subscriber)1 Calling party has ISDN access (ISDNuser)00 ISUP signaling preferred allthe way01 ISUP signaling not required allthe way11 ISUP signaling required all thewayThe combination of bits C, B, D, F, H, and G constitutes the protocol control indicator(PCI).Par.15 Information Indicators. This is a mandatory parameter in INF (Information)messages (Fig. 11.2-5). It consists of bits representing the parameters orcall-control functions that can be requested by an exchange. The bit values indicatewhether the corresponding parameter is included in the message, or whether thecorresponding service is being provided. For example:Parameter or Function Bit(s) Value(s) MeaningCalling party number (Par.8) BA 00 Not included01 Not available11 IncludedCall holding C 0 Not provided1 ProvidedCalling party category (Par.7) F 0 Not included1 Included