这是一个由2个Cisco AS5300网关组成的简单网络，一个在San Jose，另一个在Raleigh。在每一个地方都另外配制一个网守Cisco 3640。从下面的拓扑中可以看出：网守在一个简单的VoIP呼叫中并不一定需要。 下面的Cisco网守配置同一般的VoIP实现的主要区别： ● 每个网关（AS5300）向本地的网守登记。这一过程是通过h323-gateway voip接口命令来实现的 ● 在dial-peer voice 2 voip的session target指向RAS（注册、认证和状态）而不是ipv4:<ip address>。RAS定义了：网关向哪个网守登记，每个呼叫中发送人证请求和查询呼叫的状态信息 在H.323网络中，每个区域需要一个主网守来控制多个网关或多个末端H.323设备。在下面的配置中，当呼叫被转向合适的网守时，网守通过被叫号码的tech-prefix负责回应已注册的网关的IP地址。 呼叫处理 下面阐述了网守是怎么处理呼叫处理的：从Raleigh打电话到San Jose。 1． Raleigh 5300A接收到从PBX来的呼叫4085556400。这一电话号码是连接在San Jose的PBX上的。该号码与dial-peer voice 2 voip下的配置（408#）相匹配 2． 向Raleigh的网守的认证请求包括技术前缀和被叫号码：408#4085556400。4085556400匹配zone prefix命令：408……. 3． Raleigh网守把路由请求发往San Jose的网守（San Jose 3640A） 4． San Jose的网守的配置信息包括tech-prefix: 408#。所以San Jose的网守返回它自己的IP地址给Raleigh的网守 5． 这个IP地址进一步发给Raleigh 5300A（通过一个认证证实消息ACF） 6． Raleigh 5300A然后打开一个H.323呼叫通道，与San Jose的5300A建立通话 配置 Raleigh 5300A的配置信息如下： Raleigh5300A#sh run Building configuration... Current configuration: ! ! Last configuration change at 00:15:38 UTC Tue Mar 28 2000 ! NVRAM config last updated at 00:15:39 UTC Tue Mar 28 2000 ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname Raleigh5300A ! logging buffered 50000 debugging enable secret cisco ! spe 1/0 1/7 firmware location system:/ucode/mica_port_firmware ! ! resource-pool disable ! ! ! clock calendar-valid ip subnet-zero ! isdntch-type primary-5ess isdn voice-call-failure 0 mta receive maximum-recipients 0 ! ! controller T1 0 framing esf clock source line primary linecode b8zs pri-group timeslots 1-24 ! controller T1 1 clock source line secondary 1 ! controller T1 2 ! controller T1 3 ! ! voice-port 0:D ! ! dial-peer voice 1 pots answer-address 9195552001 destination-pattern 919#9195552... direct-inward-dial port 0:D prefix 919 ! dial-peer voice 2 voip destination-pattern 4085556400 tech-prefix 408# session target ras ! num-exp 6... 4085556... gateway ! interface Ethernet0 no ip address shutdown ! interface Serial0:23 no ip address ip mroute-cache isdntch-type primary-5ess isdn incoming-voice modem fair-queue 64 256 0 no cdp enable ! interface FastEthernet0 ip address 172.16.120.2 255.255.255.0 duplex auto speed auto h323-gateway voip interface h323-gateway voip id RALgk1 ipaddr 172.16.120.1 1718 h323-gateway voip h323-id RAL5300A@cisco.com h323-gateway voip tech-prefix 919# ! ip classless ip route 172.16.110.0 255.255.255.0 172.16.120.10 no ip http server ! line con 0 transport input none line 1 48 transport output lat pad telnet rlogin udptn v120 lapb-ta line aux 0 line vty 0 4 password cisco login ! ntp clock-period 17179850 ntp server 172.16.110.10 end Raleigh 3640A的配置信息如下： Raleigh3640A#sh run Building configuration... Current configuration: ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname Raleigh3640A ! logging buffered 50000 debugging enable secret cisco ! ! ! ip subnet-zero ! ip dvmrp route-limit 20000 ! ! ! interface Ethernet1/0 ip address 172.16.120.1 255.255.255.0 ! interface Serial1/0 no ip address no ip mroute-cache no fair-queue ! interface TokenRing1/0 no ip address shutdown ring-speed 16 ! ip classless ip route 172.16.110.0 255.255.255.0 172.16.120.10 no ip http server ! ! gatekeeper zone local RALgk1 cisco.com zone remote SJgk1 cisco.com 172.16.110.1 1719 zone prefix SJgk1 408....... gw-type-prefix 408#* no shutdown ! ! line con 0 transport input none line aux 0 line vty 0 4 password cisco login ! ntp clock-period 17179864 ntp server 172.16.110.10 end San Jose 5300A的配置信息如下： SanJose5300A#sh run Building configuration... Current configuration: ! ! Last configuration change at 00:15:49 UTC Tue Mar 28 2000 ! NVRAM config last updated at 00:15:50 UTC Tue Mar 28 2000 ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname SanJose5300A ! logging buffered 50000 debugging enable secret cisco ! ! ! resource-pool disable ! ! ! ip subnet-zero ! isdn voice-call-failure 0 mta receive maximum-recipients 0 ! ! controller T1 0 framing esf clock source line primary linecode b8zs ds0-group 1 timeslots 1-4 type e&m-immediate-start ! controller T1 1 clock source line secondary 1 ! controller T1 2 ! controller T1 3 ! ! voice-port 0:1 ! ! dial-peer voice 1 pots answer-address 4085556001 destination-pattern 408#4085556... direct-inward-dial port 0:1 prefix 6 ! dial-peer voice 2 voip destination-pattern 9195552... tech-prefix 919# session target ras ! num-exp 2... 9195552... gateway ! interface Ethernet0 no ip address ! interface FastEthernet0 ip address 172.16.110.2 255.255.255.0 duplex auto speed auto h323-gateway voip interface h323-gateway voip id SJgk1 ipaddr 172.16.110.1 1718 h323-gateway voip h323-id SJ5300A@cisco.com h323-gateway voip tech-prefix 408# ! ip classless ip route 172.16.120.0 255.255.255.0 172.16.110.10 no ip http server ! ! ! line con 0 transport input none line aux 0 line vty 0 4 password cisco login ! ntp clock-period 17179892 ntp server 172.16.110.10 end San Jose 3640A的配置信息如下： SanJose3640A#sh run Building configuration... Current configuration: ! ! NVRAM config last updated at 00:05:33 UTC Tue Mar 28 2000 ! version 12.1 service timestamps debug datetime msec service timestamps log datetime msec no service password-encryption ! hostname SanJose3640A ! boot system flash c3640-ix-mz.120-7.T logging buffered 50000 debugging enable secret cisco ! ! ! ip subnet-zero ! ip dvmrp route-limit 20000 ! ! interface Ethernet1/0 ip address 172.16.110.1 255.255.255.0 ! interface Serial1/0 no ip address no ip mroute-cache shutdown no fair-queue ! interface Ethernet1/1 no ip address shutdown ! ip classless ip route 172.16.120.0 255.255.255.0 172.16.110.10 no ip http server ! tftp-server flash:c3640-ix-mz.121-1.bin ! gatekeeper zone local SJgk1 cisco.com zone remote RALgk1 cisco.com 172.16.120.1 1719 zone prefix RALgk1 919....... gw-type-prefix 919#* no shutdown ! ! line con 0 transport input none line aux 0 line vty 0 4 password cisco login ! ntp server 172.16.110.10 end
