Abstract: The present invention relates to an exchange apparatus and a method for testing an exchange apparatus. The exchange apparatus includes layer 1 process normality confirming means for confirming the normality of a layer 1 process to the digital terminals by the exchange while the connecting means interconnects physically the terminals; the exchange having layer 2 logical link establishing means for inversely controlling command/response information during a logical link setting request after confirming the normality of layer 1 process to the digital terminals in the exchange, and then for establishing a layer 2 logical link in the exchange in a loop-back state. The object is to test comprehensively an exchange apparatus including the layer 1 to layer 3 processes of the primary rate interface without actually connecting the primary rate interface subscriber device.

Abstract: A plastic interlayer for lamination comprises a plastic film or sheet, at least one surface of which has a structure having many separated projections and continuous roots in the same level.