This thesis focuses on the network security of ISDN IAD(Integrated Service Digtal Network: ISDN, Integration Access Device:: IAD). Firstly, technical background of ISDN IAD is analyzed and summarized;

• 首先对ISDN IAD(Integrated Service Digtal Network:ISDN,Integration Access Device:IAD)的技术背景进行分析和总结,对它的网络安全提出了功能需求;