LRTT MEASURING CIRCUIT, COMMUNICATION DEVICE, PACKET RING NETWORK, AND LRTT MEASUREMENT PROCESSING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an LRTT (loop round trip time) measuring circuit, capable of reducing the frequency of access to a topology database and realizing high-speed LRTT measurement processings.;SOLUTION: An LRTT measuring circuit 1 has a MAC (media access control) table 14 which is independent from a topology database 3 and for storing a MAC address of a node, and an LRTT table 15 for storing LRTT measurement results, and performs LRTT measurements using the MAC table 14 and the LRTT table 15. An LRTT request generating portion 11 acquires the MAC address of the node from the MAC table 14 and sends out an LRTT request frame, of which the destination is the acquired address, to an RPR (resilient packet ring) ring 2. An LRTT response detection portion 13 detects an LRTT response frame on the RPR ring 2, and calculates the LRTT value from the contents, and then the LRTT response detecting portion 13 stores the calculation result in the LRTT table 15 and notifies the end of the LRTT measurement to the MAC table 14.;COPYRIGHT: (C)2009,JPO&INPIT