scope:

Applicability to frame mode services

The Remote Frame Handler (RFH) is an Integrated Services Digital Network (ISDN) frame handler, as defined in CCITT Recommendation Q.933 [4]:

- which is assumed to be remote with respect to the local connection-related function (refer to CCITT Recommendation I.324 [3]); and

- which is accessed by its subscribers via a two-step frame mode call establishment (CCITT Recommendation Q.933 [4], case A).

This European Telecommunication Standard (ETS) defines a manufacturer-independent interface between the local Connection Related Function (CRF) and the RFH, supporting a specific set of services. This interface is called the Remote Frame Handler Interface (RFHI).

The RFHI can operate:

a) as an ISDN network-internal interface, in case the RFH belongs to the ISDN;

b) as an inter-network interface, in case the RFH belongs to another network;

c) as a private-public network interface.

However, the existence of this specification does not preclude alternative implementations of a networkinternal interface for Frame Relay Bearer Service (FRBS) provided by a RFH.

Scope reduction

This ETS specifies the interface between the local CRF and the RFH. It defines those additional requirements that are a direct result of standardizing this interface. Requirements to the ISDN and particularly to the RFH which are inherent to the provisioning of frame relay services by the ISDN/RFH and, therefore, are not a direct result of this interface, are specified in other standards. For such requirements this ETS makes reference to those standards.

Combination of the RFHI with the Packet Handler access point Interface (PHI), as specified in ETS 300 099 [8] is outside the scope of this ETS.

Supported ISDN frame mode services and conformance statement

The RFHI specification supports all case A services as defined in ETS 300 399-2 [10]; see clause 5 for details. No other services are supported by the RFHI specification.

The RFHI may be used to offer a subset of the frame relay services supported by the RFHI specification. Conformance to the RFHI specification is ensured by conforming to the sections of the specification that are relevant for the support of the subset of frame relay services to be offered with the RFHI.