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ETSI - PRETS 300 099

Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI)

inactive
Organization: ETSI
Publication Date: 1 December 1997
Status: inactive
Page Count: 156
scope:

Implementation alternatives for ISDN packet mode services and applicability of this European Telecommunication Standard (ETS).

This ETS defines a network-internal interface for the provision of ISDN packet-mode services.

The term ISDN packet mode services is defined in such a way as to include both case B (ISDN Packet Mode Bearer Services (PMBS)), and case A (PSPDN services), as defined in ETS 300 007 [20].

If a specific implementation alternative for the provision of PMBS and PSPDN is used in an ISDN or a Global System for Mobile communication (GSM) Public Land Mobile Network (PLMN), this ETS applies. The implementation alternatives and the exact location of the interface are described below.

In CCITT Recommendation I.324 [6] local Connection Related Function (CRF) and Packet-Handling Function (PHF) are defined as being involved in the provision of PMBS. The local CRF includes the Exchange Termination (ET). Two basic implementation alternatives are mentioned in subclause 3.1.2 of CCITT Recommendation I.324 [6] and in ETS 300 007 [20]:

1) the PHF is integrated in the local CRF; and

2) the PHF is not part of the local CRF.

NOTE 1: Local CRF and PHFs are implemented with different physical equipment and in a multi-vendor environment. In addition, the Packet Handler (PH), although logically belonging to the ISDN, may be physically part of the PSPDN.

In the first case, the interface between ET and PHFs can be kept internal and proprietary. In the second case, a standardized interface between local CRF and PHFs is required. This ETS defines a manufacturer-independent interface between the local CRF and PHFs. The interface is called the Packet Handler access point Interface (PHI).

If the second implementation alternative is chosen for the provision of packet mode services in an ISDN, this ETS applies for the implementation of the PHI. The existence of this ETS does, however, not preclude the choice of the first implementation alternative in an ISDN.

Considerations for the use of the PHI in private networks and interworking between private and public networks are outside the scope of this ETS. The PHI is a network-internal interface to be used in public networks.

ISDN packet mode services supported

The full scope of services defined in ETS 300 048 [7] and ETS 300 049 [8] (case B) and in ETS 300 007 [20] (cases A and B) is supported by the PHI specification, see clause 5 for details. Subclause 5.4 contains a table giving an overview of the services, references to the relevant sections of the PHI specification and a conformance statement.

The PHI specification uses the term Packet Handler (PH) in both case A and case B services. For case A services, the PH assumes the role of the Access Unit (AU), see ETS 300 007 [20].

No other services are supported by the PHI specification.

Local and remote access to the PHI

The PHI denotes the interface between the PH and the CRF it is directly connected to (called CRF-P, see subclause 4.3). At least in the initial phase of service offerings it can be expected that the number of local exchanges in an ISDN exceeds the number of packet handlers. The PHI will thus also have to support subscribers accessing it remotely, i.e. subscriber and PH are connected to different CRFs.

Consequently the following two scenarios are considered in this ETS:

1) Local PHI Access:

An ISDN subscriber accessing packet mode services from the PH is directly connected to the CRF-P.

2) Remote PHI Access:

An ISDN subscriber accessing packet mode services from the PH is connected to the CRF-P via another local CRF (called CRF-S, see subclause 4.3) or series of CRFs (CRF-S and transit-CRFs).

In the second scenario the PHI specification defines only the interface between PH and CRF-P. The interface between CRF-S and CRF-P is thus not defined by the PHI specification.

NOTE 2: Requirements by the PHI specification on the common channel signalling system (signalling between CRF-S and CRF-P) are described in (informative) annex A.

Document History

April 1, 1998
Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI)
A description is not available for this item.
PRETS 300 099
December 1, 1997
Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI)
Implementation alternatives for ISDN packet mode services and applicability of this European Telecommunication Standard (ETS). This ETS defines a network-internal interface for the provision of ISDN...
January 1, 1996
Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI) Second Edition
This European Telecommunication Standard (ETS) provides specifications for the standardisation of the characteristics of transmit/receive Very Small Aperture Terminals (VSATs) operating as part of a...
January 1, 1992
Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI)
Implementation alternatives for ISDN packet mode services and applicability of this specification This specification defines a network-internal interface for the provision of ISDN packet-mode...
January 1, 1991
Integrated Services Digital Network (ISDN) Specification of the Packet Handler Access Point Interface (PHI)
Implementation alternatives for ISDN packet mode services and applicability of this European Telecommunication Standard (ETS). This specification defines a network-internal interface for the...

References

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