摘要： 介绍了系统的结构框架，重点说明了利用PCI 接口控制电路、网络接口电路和逻辑控制电路实现系统的自适应网络功能和内外网的安全物理隔离卡，该卡能自动地识别所连接网络设备的速率和工作方式，并将工作方式和速率调整到正确的模式与之相适应。系统的管理软件包括安全策略管理模块、安全审计模块、数据库记录交换模、文件交换模块和邮件交换模块，以实现内外网数据安全高效的交换和管理，同时使用Windows DDK 实现了基于NDIS 的硬件驱动程序。这些关键技术的实现对相关课题研究具有普遍性的意义。

关键词: 物理隔离；内外网；PCI 总线；设备驱动程序

Abstract: This paper provides the framework of the system. Then the hardware of the system, including the PCI interface control circuits, the network interface circuits and logic control circuits, is designed to adapt its operation speed and mode to the network automatically and isolate the internal and external network securely; the software of the system, including the security strategy management module, the security audit module,the database record exchanging module, the file exchanging module and the mail exchanging module, is designed to exchange and manage the data transference between the internal and external network efficiently. Finally the driver of the system is implemented with Windows DDK based on NDIS. The technological cruxes discussed in the paper have practical values for related subjects

Key words: Physical disconnection; Internal and external network; PCI bus; Device driver