故障现象
笔者某次配置了一个AM模块。出现了一个奇怪的问题。配置好后，拨入时没有Modem拨号声。只有电话的声。并且音指示灯也不亮。当笔者拔下模块上的电话线时。指示灯亮了。
配置
620#sh run
Building configuration...
Current configuration : 866 bytes
!
version 12.2
service timestamps debug uptime
service timestamps Jog uptime
no service password-encryption
!
hostname2620
enable secret 5 $1$pUrf$9xGOg.zyxKawi9NljLHHr1
usernameuser password 0 Cisco
ip subnet-zero
!
!
no ip DOmain-lookup
!
!
!
!
interface FastEthernet0/0
ip address 136.0.0.254255.255.0.0
duplex auto
speed auto
!
interface Group-Async1
ip unnumbered FastEthernet0/0
encapsulation ppp
async default routing
async mode interactive 读书人IT频道reader8.net/exam/jisuanji/