出于网络和信息安全考虑,按照国家主管安全部门的规定,不少政府部门建有三张网:一是政府部门的内网,通常被部门本身定为涉密网,承载内部的日常网上办公系统。二是从中央政府部门连接到下一级地方政府部门的全国纵向网,又称部门专网,主要提供视频会议服务,承载上报数据和文件等 For network and information security considerations, in accordance with the provisions of the competent national security department, many government departments have three networks: First, the government departments within the network, the department itself is usually classified as secret network, carrying the internal daily online office system . Second, from the central government departments connected to the next level of local government departments of the national vertical network, also known as departmental network, the main provider of video conferencing services, carrying data reported and documents