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 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)@ see ETS 300 007 [20]. This specification shall be used if a specific implementation alternative for the provision of these services is used in an ISDN. The implementation alternatives and the exact location of the interface are described in the following paragraphs. 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 packet mode bearer services (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 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. Local CRF and PHFs are implemented with different physical equipment and in a multi-vendor environment. In addition@ the 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 standardised interface between local CRF and PHFs is required. This specification 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 specification shall be used for the implementation of the PHI. The existence of this specification 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 standard. The PHI is a network-internal interface to be used in public networks.
ETS 300 099-1992 history
1998ETSI ETS 300 099-1998 Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI) (Second Edition;)
1997ETSI PRETS 300 099-1997 Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI) Second Edition
1996ETSI PRETS 300 099-1996 Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI) Second Edition
1992ETSI ETS 300 099-1992 Integrated Services Digital Network (ISDN); Specification of the Packet Handler Access Point Interface (PHI)
1991ETSI PRETS 300 099-1991 Integrated Services Digital Network (ISDN) Specification of the Packet Handler Access Point Interface (PHI)