Design and implementation of an ATM cell controller for FR/ATM interworkign system

摘要

In this paper,we described on hte design and implementationof an ATM cell controler for a high speed interface between FRIM (Frame Relay Interworking Module) and ALS (ATM Local switching subsystem).In upstream direction,the ATM cell controller receives a cell stream from 16 Frame relay subsciriber access boards,and performs UPC (Usage Parameter OCntrol),cell head translation,EHEC generation,AAL type 5 segmentation,and ATM switch interface function.In reverse directin,the ATM cell controller classifies the received cell stream through an ATM switch into usercells and IPC (Inter Processor Communicaiton) cells,and performs 64/53 octets conversin,AAL type 5 cell reassembly,HEC genration,and handling of usr cells,IPC cells,and OAM cells.And these functins are implemented by using FPGA,and we have verified the whole ATM cell controler functins by connecting protocol tester,Frame relay subscriber board and an ATM switch.