| 摘要 |
PROBLEM TO BE SOLVED: To securely avoid CPU congestion by monitoring the occurrence of a congestion state where the use rate of a central processing unit in a self- system is higher than a prescribed value and abolishing a part of received frames when congestion is detected. SOLUTION: A congestion monitoring part 205 always monitors the use rate of a CPU issues a CPU congestion notice to an IP routing part 201 when the CPU use rate exceeds a congestion judgment threshold. When the CPU use rate returns to a value which is not more than the congestion judgment threshold, a CPU congestion release notice is issued to the IP routing part 201. the IP routing part 201 gives an IP frame transmission stoop instruction and an IP frame transmission resumption instruction to the IP part 202 when the CPU congestion notice and the CPU congestion release notice from the congestion monitor part 205 are given. When the system becomes the CPU congestion state by the functions of the congestion monitoring part 205, the IP routing part 201 and the IP part 202, an IP frame from a LAN line-side is abolished. |
