External dial tone

If the DTNE parameter is set in the COT of an incoming seized analog trunk, an external dial tone is always fed to the calling node, irrespective of whether the incoming call results in a terminating line or a transit line.

If the DTNE parameter is set in the COT of an incoming seized digital trunk, an external dial tone is fed to the calling node, if the incoming call results in a transit line in the trunk route about which no dialing information has yet been sent for selecting the external destination.

Only one of the COT parameters for the tone types may be set: Either PAR=DTNE ... external dial tone or PAR=NTON ... no tone or PAR=WTINT ... internal dial tone or PAR=VM ... Voice Mail or PAR=ANNC ... local announcement. If this is not followed, then a COT cannot be set up or modified. Error messages F04 or F05 are output.

F04: No parameter value specified for tone type NTON, DTNI, DTNE, VM or ANNC

F05: Only one of the following tone types may be specified: NTON, DTNI, DTNE, VM or ANNC

COT Classes of Trunks: Types of tone: NTON, DTNI, VM, ANNC

COP Classes of Parameters: DTN with analog trunks

ZAND Central System Data: SIU ... Assigned SIU tone

Analog and digital interface circuits and tie trunk circuits

For example:

ANALOG - Protocols for analog trunks

CORNV33 - CorNet protocol

CORNV33R - CorNet protocol

ECMA1 - ECMA QSIG V1 protocol

ECMA1R - ECMA QSIG V1 protocol

ECMAV2 - CorNet-NQ Issue 2.1 Dec. 96 Basic ETSI

ECMAV2R - QSIG ETSI ETS 300 172 3rd. with SS 2nd.