scope:

This European Telecommunication Standard (ETS) specifies the stage three of the supplementary service interactions for the pan-European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators at the T reference point or coincident S and T reference point (as defined in ITU-T Recommendation I.411 [29]) by means of the Digital Subscriber Signalling System No. one (DSS1) protocol. Stage three identifies the protocol procedures and switching functions needed to support a telecommunication service (see CCITT Recommendation I.130 [26]).

This ETS specifies the interactions between the Advice of Charge (AOC), Completion of Calls to Busy Subscriber (CCBS), Call Deflection (CD), Call Forwarding Busy (CFB), Call Forwarding No Reply (CFNR), Call Forwarding Unconditional (CFU), Calling Line Identification Presentation (CLIP), Calling Line Identification Restriction (CLIR), Connected Line Identification Presentation (COLP), Connected Line Identification Restriction (COLR), Conference call, add-on (CONF), Explicit Call Transfer (ECT), Closed User Group (CUG), Call Waiting (CW), Direct Dialling In (DDI), Freephone (FPH), Call Hold (HOLD), Malicious Call Identification (MCID), Multiple Subscriber Number (MSN), Subaddressing (SUB), Terminal Portability (TP), User-to-User Signalling (UUS) and Three-Party (3PTY) supplementary services.

In addition, this ETS specifies the protocol requirements at the T reference point where the supplementary services are provided to the user via a private ISDN.

This ETS does not specify the additional protocol requirements where the supplementary services are provided to the user via a telecommunications network that is not an ISDN.

The protocol for individual supplementary services is specified in other ETSs:

AOC: ETS 300 182-1 [13];

CCBS: ETS 300 359-1 [20];

Diversion services: ETS 300 207-1 [17];

CLIP: ETS 300 092-1 [6];

CLIR: ETS 300 093-1 [7];

COLP: ETS 300 097-1 [8];

COLR: ETS 300 098-1 [9];

CONF: ETS 300 185-1 [14];

ECT: ETS 300 369-1 [21];

CUG: ETS 300 138-1 [11];

CW: ETS 300 058-1 [3];

DDI: ETS 300 064-1 [5];

FPH: ETS 300 210-1 [18];

HOLD: ETS 300 141-1 [12];

MCID: ETS 300 130-1 [10];

MSN: ETS 300 052-1 [1];

SUB: ETS 300 061-1 [4];

TP: ETS 300 055-1 [2];

UUS: ETS 300 286-1 [19];

3PTY: ETS 300 188-1 [15].

When two or more supplementary services are implemented, the protocol interactions are defined in this ETS. These interactions are applicable to the telecommunication services as specified for the individual supplementary services.

This ETS is applicable to equipment supporting supplementary services, to be attached at either side of the T reference point or coincident S and T reference point when used as an access to the public ISDN.

Further parts of this ETS specify the method of testing required to identify conformance to this ETS.