Public packet switched data networks, international plans and standards

The key to the interconnection of any telecommunication service on an international basis is the establishment at an early stage of internationally agreed Recommendations relating not only to the services and facilities to be provided but also to the methods to be adopted to set-up and clear-down calls, the routing of traffic, the setting of acceptable charges and the numbering plan to be adopted. Within the CCITT considerable programs has now been made in the setting of standards for public data services based on the packet mode of transmission, and this has enabled the common carriers to proceed with the establishment of services both nationally and internationally to meet customer demands. This paper considers, the basic standards which now apply to such services and gives an indication of the common carriers current plans including details of the routing and signaling philosophy which needs to be adopted to permit satisfactory interworking. Some indication of the various technological solutions adopted is also given taking into account the varying demands for service and the traffic charecteristics. Several problems, however, in regard to protocols and the handling of terminals still need to be resolved and these are highlighted together with possible trends in their solution. In conclusin, the paper refers to the impact which the introduction of circuit-switched data services and a possible integrated services digital network could have on longer term trends in the development of packet-switched data services.