This European Telecommunication Standard (ETS) identifies the Interwor king Functions (IWF s) and requirements for the interworking between a GSM PLMN and a Packet Switched Public Data Network/Integrated Service s Digital Network (PSPDN/ISDN) for the support of packet services in G SM PLMNs. In the GSM PLMN context the packet services are associated with bearer services and are described in GSM 02.02. The generally defined GSM PL MN user-network access as defined in the respective GSM specifications (see references) forms the basis for defining the particularities for the provision of packet services to the GSM PLMN subscribers. Network internal interfaces for the support of packet services in the pan-Eur opean ISDN are defined in ETSI standards, which are also taken as a ba sis. User-network access and network internal interfaces are defined to pro vide the packet services.
