Being the device which possesses the frame buffer expedient which accumulates buffer information the case of the cell assembly processing with cell assembly processing expedient and the aforementioned

摘要

PROBLEM TO BE SOLVED: To perform an assembling and disassembling processing for AAL5 on which the priority of a higher-hierarchy layer is reflected by equipping a next processing judging means with a 2nd priority part which judges whether a frame is sent or discarded according to the header of a cell or in-payload higher-hierarchy information when sending a frame obtained from a received by a cell assembling means to a next processing. SOLUTION: A cell disassembling processing part 2 receives a frame and a corresponding frame descriptor by an LSI 1 through a transmit frame information storage part 13A and makes a priority/nonpriority judgement (priority control) from the priority specified from a higher layer at the same time. When the disassembling processing for a cell is affected, a frame of low priority is discarded and a frame with top priority is processed without any delay. This discharging priority function is provided for the LSI 1. In the higher- hierarchy, frames with high priority are never discarded even if the frames with high priority congest.