2/5 Apparatus and method for converting AAL2/AAL5

摘要

PURPOSE: An AAL2/AAL5 converting apparatus and method are provided to improve a cell transfer rate according to a protocol conversion and reduce a hardware overhead by implementing the protocol conversion by hardware in converting from AAL2 to AAL5 and its reverse converting, and solve the problem of a memory shortage and cell delay by storing a portion of a packet and converting it. CONSTITUTION: An AAL2 receiving unit(100) demultiplexes an inputted AAL2 ATM cell, extracts an AAL2 CPS packet, and outputs the extracted AAL2 CPS packet to an AAL5 transmitting unit(200). An AAL5 transmitting unit(200) receives the AAL2 CPS packet, assembles the received AAL2 CPS packet as an AAL5 ATM cell and transmitting it. An AAL5 receiving unit(300) receives the AAL5 ATM cell, disassembles the AAL5 ATM cell into a packet and outputs it to an AAL2 transmitting unit(400). An AAL2 transmitting unit(400) receives the AAL5 ATM cell, converts the received AAL5 ATM cell into an AAL2 ATM cell, and multiplexes and outputs it. An SRAM#1(101) temporarily stores a data required for demultiplexing the ATM cell which has been inputted in a multiplexed state. A CAM#1(102) stores a parameter required for demultiplexing the multiplexed ATM cell. An SRAM#3(201) stores a length field and a CRC field of the AAL5 transmitting unit(200). A CAM#3(202) stores a parameter required for converting the CPS packet into an AAL5 ATM cell. An SRAM#4(301) discriminates whether the ATM cell received by the AAL5 receiving unit(300) is a more data or a final data, and stores length information and the latest charged load information in case that the received ATM cell is the more data. A CAM#4(302) stores a table for extracting an address for discriminating an SRAM area by VP/VC. An SRAM#2(401) temporarily stores the received CPS packet. A CAM#2(402) stores a parameter for transmitting the CPS packet to the AAL2.