Intergrated Services Digital Network ISDN ISDN Small office

第十八章 综合业务数字网 （Intergrated Services Digital Network, ISDN)

什么是 ISDN Small office Digital PBX Provider network Telecommuter Home office Central site ISDN 能够提供声音、视频、数据等传输服务 Cisxo Education Solution 3

ISDN 访问方式 Channel Capacity Mostly Used for B 64 kbps D 16/64 kbps Signaling information (LAPD) Circuit-switched data (HDLC, PPP) NT 1 BRI Service provider network D 2 B PRI CSU/DSU D 23 or 30 B BRI 和 PRI 是ISDN的两种常见访问方式 Cisxo Education Solution 5

BRI 呼叫处理 ISDN service provider 1 3 4 ISDN Switch 2 SS 7 ISDN Switch B channel(s) D channel/SS 7 signaling Cisxo Education Solution 6

ISDN 功能和参考点 Local loop TE 1 S NT 2 T NT 1 U ISDN Terminal TE 2 Existing Terminal Cisxo Education Solution R Service provider network TA Terminal Adapter �硬件设备的主要功能 �参考点的划分和不同的接口 7

Cisco ISDN BRI 接口 Native ISDN interface—int bri 0 TE 1 bri 0 Service provider network NT 1 S/T bri 0 TE 1 U NT 1 TE 2 R S 0 TA S/T NT 1 Nonnative ISDN interface—int serial 0 (EIA/TIA-232, V. 35, X. 21) Cisxo Education Solution 8

什么是按需拨号路由(DDR) Dallas Corporate PSTN Chicago I need to send data to Dallas. ISDN �需要时建立连接 �数据通讯完成时切断 �ISDN 或 PSTN Cisxo Education Solution 9

何时使用 DDR Telecommuter Headquarters Vendor �定期连接 �小数据量传输 Cisxo Education Solution 10

DDR 作过程 “Interesting” packet arrives DCE 1. 决定目标路径 Cisxo Education Solution 11

DDR 作过程 “Interesting” packet arrives DCE 1. 决定目标路径 2. 指明建立 DDR 通话的触发条件 Cisxo Education Solution 12

DDR 作过程 “Interesting” packet arrives Dial connection DCE ISDN or Basic Service 1. 决定目标路径 2. 指明建立 DDR 通话的触发条件 3. 检查拨号信息 Cisxo Education Solution 13

DDR 作过程 “Interesting” packet arrives Dial connection DCE ISDN or Basic Service 1. 决定目标路径 2. 指明建立 DDR 通话的触发条件 3. 检查拨号信息 4. 数据传输 5. 会话结束 Cisxo Education Solution 14

配置 DDR “Interesting” packet arrives DCE 1 Cisxo Education Solution 指定静态路由—使用哪条路由? 15

配置 DDR “Interesting” packet arrives Dial connection DCE 1 2 3 Cisxo Education Solution ISDN or Basic Service 指定静态路由—使用哪条路由? 指定触发数据—什么样的数据能够建立连接? 配置拨号信息—播叫哪个号码? 17

任务 1: 指定路由信息 Subnet 10. 40. 0. 0 10. 1 Home bri 0 5551000 10. 1. 0. 2 ISDN bri 0 5552000 Central Subnets 10. 0. 0 10. 20. 0. 0 ip route 10. 40. 0. 0 255. 0. 0 10. 1 Specify address of next hop router ip route 10. 0. 0 255. 0. 0 10. 1. 0. 2 ip route 10. 20. 0. 0 255. 0. 0 10. 1. 0. 2 Network prefix and prefix mask Cisxo Education Solution 18

任务 2: 指定触发条件 • 没有访问列表 dialer-list 1 protocol ip permit 所有的数据都可以建立连接 • 有访问列表 dialer-list 1 protocol ip list 101 access-list 101 deny tcp any eq ftp access-list 101 deny tcp any eq telnet access-list 101 permit ip any Deny FTP Deny Telnet 除了FTP和Telnet以外的数据都可以建立连接 Cisxo Education Solution 19

任务 3: 配置拨号信息 hostname Home ! isdn switch-type basic-5 ess ! interface BRI 0 ip address 10. 1 255. 0 encapsulation ppp dialer idle-timeout 180 dialer map ip 10. 1. 0. 2 name Central 5552000 dialer-group 1 no fair-queue ppp authentication chap ! router rip network 10. 0 ! no ip classless ip route 10. 0. 0 255. 0. 0 10. 1. 0. 2 ip route 10. 20. 0. 0 255. 0. 0 10. 1. 0. 2 ! dialer-list 1 protocol ip permit Cisxo Education Solution �根据实际情况在端口 上设置拨号信息 这两个值要匹配 20

任务 3: 配置拨号信息 How do I get to subnetwork 10. 0. 0? 10. 1 Home bri 0 5551000 10. 1. 0. 2 ISDN bri 0 5552000 interface BRI 0 ip address 10. 1 255. 0 encapsulation ppp dialer idle-timeout 180 dialer map ip 10. 1. 0. 2 name Central 5552000 dialer-group 1 no fair-queue ppp authentication chap Cisxo Education Solution Central Subnets 10. 0. 0 10. 20. 0. 0 Number to dial Remote host name Used for PPP CHAP 21

DDR 配置总述 3 1 2 Cisxo Education Solution hostname Home ! isdn switch-type basic-5 ess ! interface BRI 0 ip address 10. 1 255. 0 encapsulation ppp dialer load-threshold 125 either dialer idle-timeout 180 dialer map ip 10. 1. 0. 2 name Central 5552000 dialer-group 1 ppp authentication chap ! router rip network 10. 0 ! no ip classless ip route 10. 0. 0 255. 0. 0 10. 1. 0. 2 ip route 10. 20. 0. 0 255. 0. 0 10. 1. 0. 2 dialer-list 1 protocol ip permit ! 22

DDR 配置命令 Router(config-if)#dialer load-threshold load [ outbound | inbound | either ] �设置启用第二个通道传输数据的条件 Router(config-if)#dialer idle-timeout seconds �设置会话切断前的延迟时间 Cisxo Education Solution 23

DDR 配置举例 access-list 101 permit tcp any eq smtp access-list 101 permit tcp any eq telnet dialer-list 1 protocol ip list 101 ! ip route 192. 168. 12. 0 255. 0 10. 108. 126. 2 ip route 192. 168. 14. 0 255. 0 10. 108. 126. 2 ! interface bri 0 ip address 10. 108. 126. 1 255. 0 dialer-group 1 dialer map ip 10. 108. 126. 2 name B 5551234 ! dialer idle-timeout 300 10. 108. 126. 1 A Cisxo Education Solution 10. 108. 126. 2 ISDN B Access list defining interesting packets on Cisco A Static routes to reach destination Interface configuration for DDR Time to wait before dropping call Subnets 192. 168. 12. 0 192. 168. 14. 0 24

查看ISDN 信息 Router#ping or telnet • 触发线路的连接 Router#show dialer • 显示线路的连接状态 Router#show isdn active Router#show isdn status Router#show ip route Cisxo Education Solution • 使用ISDN 时, 会话建立时的状态显示 • 显示 ISDN 的连接状态 • 显示路由表 25

查看ISDN 信息 Router#debug isdn q 921 • 显示 ISDN 第二层信息 Router#debug isdn q 931 • 显示 ISDN 会话建立和切断情况 Router#debug dialer • 显示会话建立和切断状态 Router(config-if)#shutdown • 在端口上清除已经建立的连接 Cisxo Education Solution 26