XX局网络系统方案建议书目录1、前言....................................................62、系统概述与需求...........................................72.1系统建设的必要性.......................................72.2系统建设概况...........................................72.3总体需求...............................................72.4建网目的...............................................83、局域网技术现状分析与技术概述.............................93.1网络技术选择.........................................103.2网络设备的系统结构...................................103.3虚拟专用网络(VPN)....................................113.4路由功能.............................................113.5容错功能.............................................113.6网络管理.............................................114、网络方案概述............................................124.1网络设计思想..........................................124.2网络逻辑结构..........................................145、网络实现................................................155.1系统需求..............................................155.2网络实现技术..........................................155.2.1主干网............................................155.2.2各子网设计........................................165.2.3远程服务..........................................165.2.4与外部网络的连接..................................165.2.5网络物理拓扑结构..................................175.3外连方式..............................................175.3.1PSTN(电话拨号)....................................185.3.2ISDN(综合业务数据网)..............................185.3.3DDN(数字数据网)...................................205.3.4X.25(公共分组数据交换网)..........................215.3.5帧中继............................................225.4网络设备选择..........................................235.4.1交换机............................................235.4.2路由器............................................245.4.3远程访问服务器....................................245.4.4服务器............................................265.5系统平台..............................................266、技术重点与难点..........................................276.1子网划分与地址规划....................................276.2虚拟局域网的划分......................................276.3增强IP组播(IPMULTICAST)能力...........................287、安全性..................................................287.1网络设计..............................................287.2应用软件..............................................297.2.1用户口令加密存储和传输:..........................297.2.2分设操作员........................................297.2.3日志记录和分析....................................307.3网络配置..............................................307.3.1路由..............................................307.3.2防火墙............................................307.4系统配置..............................................317.4.1网络服务程序......................................317.4.2数据库安全配置....................................317.5通信软件..............................................328、维护....................................................338.1系统维护..............................................338.2支持与服务............................................348.2.1支持和服务范围.................