POLPAK-the first public data network in Poland

POLPAK is the commercial name for a Polish packet switched network based on X.25 protocol. The POLPAK network was built as the first public data network in Poland and has been in operation since June 1992. This paper describes the general topology of the network, the architecture of the switches, and the structure of network management and charging. The network has a capability of international calls as well as connections to internal PSTN and telex networks. The paper also describes all addressing methods used in POLPAK, especially for the international traffic.