Backward call indicators

           8  7  6  5  4  3  2  1
        1  H  G  F  E  D  C  B  A
        2  P  O  N  M  L  K  J  I

B A - Charge indicator (Note 1)
0 0 - no indication
0 1 - no charge
1 0 - charge
1 1 - spare

NOTE 1 - The interpretation of these bits depends only on the charging exchange.

D C - Called party's status indicator
0 0 - no indication
0 1 - subscriber free
1 0 - connect when free (national use)
1 1 - spare

F E - Called party's category indicator
0 0 - no indication
0 1 - ordinary subscriber
1 0 - payphone
1 1 - spare

H G - End-to-end method indicator (Note 2)
0 0 - no end-to-end method available (only link-by-link method available)
0 1 - pass-along method available (national use)
1 0 - SCCP method available
1 0 - pass-along and SCCP methods available (national use)


I - Interworking indicator (Note 2)
0 - no interworking encountered (Signalling System No. 7 all the way)
1 - interworking encountered


J - End-to-end information indicator (Note 2) (national use)
0 - no end-to-end information available
1 - end-to-end information available


K - ISDN user part indicator (Note 2)
0 - ISDN user part not used all the way
1 - ISDN user part used all the way

L - Holding indicator (national use)
0 - holding not requested
1 - holding requested


M - ISDN access indicator
0 - terminating access non-ISDN
1 - terminating access ISDN


N - Echo control device indicator
0 - incoming echo control device not included
1 - incoming echo control device included



P O - SCCP method indicator (Note 2)
0 0 - no indication
0 1 - connectionless method available (national use)
1 0 - connection oriented method available
1 1 - connectionless and connection oriented methods available (national use)

NOTE 2 - Bits G-K and O-P constitute the protocol control indicator.