scope:

This ECMA Standard specifies control aspects of standardized circuit mode basic services which may be supported by Private Telecommunication Networks (PTN).

NOTE 1

Supplementary services are described in olher ECMA Standards.

Service specifications are produced in three stages, according to the method described in Standard ECMA-134, which is based on the method used by CCITT Rec. I.130 and Rec. O.65 and ETSI. This Standard contains the Stage 1 and Stage 2 specifications of the services. Stage 1 (clauses 5 to 11) describes the services as seen by users of PTNs. Clauses 5,6 and 7 describe the common aspects of the services and clauses 8,9,10 and 11 describe those aspects which are service-dependent. Stage 2 (clauses 13,14,15 and 17) identifies the functional entities involved in the basic services and the information flows between them. Clause 12 describes interworking with a public ISDN.

NOTE 2

Stage 3, the definidon of the networking and access signalling protocols to support the basic services, will appear in separate Standards.

The purpose of the Stage 1 and Stage 2 specifications is to guide and constrain the work on signalling protocols at Stage 3, and therefore this Standard is concerned mainly with the control aspects of services. The properties of the user information are described for the different basic services which have to be controlled. Detailed requirements of user information protocols and switching functions are outside the scope of this Standard.

NOTE 3

The services specified are compatible with the equivalent services specified by CCITT and ETSI for public ISDNs. CCITT spedfjcalions of these serl'ices are to be found in Rec. I.220, I.230, I.231 (Stage 1), Q.71 (Stage 2), I.240, and I.241.

This Standard encompasses the following basic services:

- Circuit Mode 64 kbit/s Unrestricted 8 kHz Structured Bearer Service Category;

- Circuit Mode 64 kbit/s 8 kHz Structured Bearer Service Category Useable for Speech Information Transfer;

- Circuit Mode 64 kbit/s 8 kHz Structured Bearer Service Category Useable for 3,1 kHz Audio Information Transfer;

- Telephony Teleservice;

- Teletex Teleservice;

- Telefax 4 Teleservice;

- Videotex Teleservice.

NOTE 4

Service specifications are based on in information concerning the corresponding public ISDN service available at time of publication of this Standard.

Negotiation of service at call establishment time and change of service during a call are outside the scope of this Standard.

A Stage 3 Standard shall be in conformance with the Stage 1 and Stage 2 specifications contained in this Standard, if the signalling protocols and equipment behaviour specified in the Stage 3 Standard are capable of being used in a PTN which supports any or all of the basic services specified in this Standard. In particular, the Stage 3 Standards shall be adequate for the support of:

- common aspects of the control of basic services, as seen by the PTN user, as specified in clauses 5 and 6;

- the control of the individual basic services specified in clauses 8, 9, 10 and 11;

- the functional entities, functional entity allocations and information flows identified in clauses 13, 14, 15 and 17;

- and the interworking with the ISDN specified in clause 12.