CPLD-based switching circuit

Abstract

The invention discloses a CPLD-based switching circuit which can be applied to a network security device. The circuit comprises a bistable relay which is connected with the network interface of the network security device to switch a data link, a relay control circuit which is connected with the bistable relay to drive the relay control circuit of the bistable relay, a collecting circuit which is connected with the voltage input end of the network security device to collect the electrical signal of the network security device and output the collected signal, and the CPLD which is connected with the collecting circuit, the CPU of the network security device and the relay control circuit to control the operating state of the relay control circuit based on the collected signal or a signal transmitted by the CPU. When the network security device fails, the CPLD controls the relay control circuit to drive the bistable relay to switch the data link, so that a communication network is directly physically turned on. Communication interruption caused by the single point failure of the network security device is avoided. Normal communication between networks is ensured.

Description

technical field [0001] The invention relates to the field of network security equipment, in particular to a switching circuit based on CPLD. Background technique [0002] With the rapid development of information networks, the communication between networks is getting closer and closer. However, due to the natural openness of the network, there are more and more security issues in communication between networks. Therefore, the communication security between networks has also been paid more and more attention. . [0003] In the prior art, in order to ensure safe communication between networks, network security devices are applied between networks, so that network packets sent from one network to another network need to be analyzed and processed by the network security device first, and only after confirmation After there is no threat, the processed network packet is forwarded to another network according to the predetermined routing rules to complete the secure communication...

AI Technical Summary

Problems solved by technology

Therefore, once the network security device has a single point of failure, it cannot forward the upstream traffic to the downlink, resulting in the interruption of communication between networks

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