scope:

This ETS specifies two profiles:

- Profile A covers the March 1994 version of ETS 300 325 including additional protocols and operating system extensions.

- Profile B describes an alternative interface access that is bit compatible with COMMON-ISDN-API (CAPI 2.0 - January 1994).

Conformity to this ETS can only be achieved if - and only if - both, Profile A and Profile B are implemented in the realization of this HPCI for ISDN.

The interface accesses are offered in a way which guarantees binary compatibility to applications conforming to either specification. The code given in the present document, between the interface and the hardware, may or may not be common to both interface accesses. The code for the interface accesses shall comply with the definitions made for each interface, independently of whether the code is common or only able to drive one of the interface specifications. Future enhancements can be performed in a way which do not destroy this binary compatibility.

Consequently, this ETS maintains both descriptions (ETS 300 325 and COMMON-ISDN-API v2.0) besides a part which contains common aspects and overall features.

With this development, future implementations will ensure cross-compatibility between both specifications.

The HPCI described in this ETS accesses and administers the following services:

- bearer services as defined in ETS 300 102-1 [2];

- supplementary services as defined in ETS 300 196-1 [7];

- Virtual Circuit (VC) or Permanent Virtual Circuit (PVC) Bearer Services on the B- and D-channels.

It:

- covers both basic and primary rate ISDN access;

- is independent of operating systems, hardware and programming languages. It provides language and operating system binding for common operating system environments;

- supports concurrent applications;

- supports concurrent protocol stacks related to data exchange;

- supports application access to multiple channels on multiple ISDN accesses;

- provides the Open Systems Interconnection (OSI) connection-mode network service as defined by ITU-T Recommendation X.213 [6] using the method defined in ISO 9574 [9];

- provides an interface for applications requiring direct control of ISDN services;

- shows the impact of security issues on the interface;

- has been defined to allow future extension of functionality;

- supports Dual Tone Multi Frequency (DTMF) access.

Further standards specify the method of testing and detailed application specific requirements to determine conformance based on this ETS.