| 摘要 |
<p>PURPOSE: To avoid waste and to accelerate an error detection code calculation processing speed by performing an error detection code calculation processing to be performed before and after protocol conversion only once to an overlapping part in transmission information. CONSTITUTION: Cells inputted from an ATM switch 509 are stored in a buffer 505, then read in a processor 501, reconstituted into packets in a memory 503, ATM-FR converted and transmitted through an FR-PHY 507 to a line. On a reception side, when layer 2 packets are detected in the FR-PHY 506, data are transmitted to the memory 503 in the FR-ATM conversion process of the processor 501 and the packets are converted into an AAL 5 form, divided into the cells, written in a cell buffer 504 for each connection and outputted to the ATM switch 509. In an error detection processing at the time of the protocol conversion in transmission and reception, for a part whose contents after the conversion do not change, a processing result on a transmission side is utilized and the error detection processing is omitted on the reception side.</p> |
