Connectivity Fault Management Research And Realization Based On Auxiliary CPU

Ethernet was originally designed for the LAN, because the LAN has a higher reliability and stability, it has not been established early in the design of Ethernet management and maintenance mechanisms. MAN and WAN networks are rapidly expanding in the link length and size, so the Ethernet OAM mechanisms become a necessity development trend. This paper analyzes the Ethernet OAM technologies based on the CFM protocol, which uses Auxiliary CPU-based research program, achieves IEEE 802.1ag agreement CCM transmission time interval of 3.3ms, 10ms, and 100ms for rapid detection CFM function.Paper introduces the system's hardware and software environment, analyzes the continuity check, loop back and link trace, and enables the linkage function of CFM and SMLK. Paper highlights the system's software design, completes the following major features: established the communication mechanism IPC/RPC between main CPU and auxiliary CPU, to resolve the information exchange between Main CPU and auxiliary CPU about configuration management, event monitoring, message processing sub-modules; establishes a HASH table and a MEP list to find the MEP to address packets at auxiliary CPU; designs an improved FNG state machine which is combined Special fault shielding mechanism with alarm mechanism of the priority level, and the state machine can reflect the high-level alarm, single display repetitive fault alarms, not show transient fault alarms.The Ethernet OAM works in the link layer. It is characterized by fastering than the original IP layer to detect malfunctions, and better safeguards the Ethernet business; achieve a significant business in less than 50ms fault detection and recovery; when a network failure occurs, it will automatically open link tracking feature, send LTM/LTR packet, the process will also be recorded, so that network administrators can later view the fault response time and path and other information.Finally, complete system testing with switches of S7500E series. Test results show that the auxiliary CPU send and receive text reported stable, reliable, and with the original function of the slow link detection CFM well. At present, the system has been successfully applied to a fault management system of a country's telecoms operators.