Abstract: A method used for establishing an optimized path between two endpoints in a transmission network including subnetworks is provided. In the method, two endpoints and route selection elements are specified, a first route search is performed to search for route candidates each of which connects subnetworks by using data on network resources according to the route selection elements, and the route candidates is stored in a dynamic routing table. Then, at least a route candidate is selected as a selected route candidate according to the route selection elements, and a second route search is performed to search for a route connecting network elements in each subnetwork on the selected route candidate.

Abstract: A method used for establishing an optimized path between two endpoints in a transmission network including subnetworks is provided. In the method, two endpoints and route selection elements are specified, a first route search is performed to search for route candidates each of which connects subnetworks by using data on network resources according to the route selection elements, and the route candidates is stored in a dynamic routing table. Then, at least a route candidate is selected as a selected route candidate according to the route selection elements, and a second route search is performed to search for a route connecting network elements in each subnetwork on the selected route candidate.

Abstract: An electrically insulating powdery material with a volume resistivity of at least 1 .times. 10.sup.10 ohms-cm, which consists of a calcined product of a mixture of magnesium oxide with boron oxide and if desired, at least one of titanium, iron and chromium oxides and has a special novel structure wherein a core of magnesium oxide particles is surrounded by a sheath of a double oxide of the magnesium oxide and the boron oxide and if desired, the other metal oxide. This insulating powdery material is produced by calcining the above mixture under specified calcining conditions determined by a special temperature-time relation. A thermally conducting and electrically insulating resin composition especially having superior electrical properties under high temperature-high humidity conditions can be prepared using the above powdery material as a filler.