// ROUTER A　

username routerb password cisco

isdn switch-type basic-ni

interface bri0/0

  ip address 196.1.1.1 255.255.255.0

  encapsulation ppp

  ppp authentication chap

  isdn spid1 7400403

  dialer map ip 196.1.1.2 name routerb broadcast 7040405

  dialer idle-timeout 90

  dialer-group 1

  dialer-list 1 protocol ip permit

  ppp multilink

  dialer load-threshold 1 

// ROUTER B

username routera password cisco

isdn switch-type basic-ni

interface bri0/0

  ip address 196.1.1.2 255.255.255.0

  encapsulation ppp

  ppp authentication chap

  isdn spid1 7040405

  dialer map ip 196.1.1.1 name routera

  dialer idle-timeout 90

  dialer-group 1

  dialer-list 1 protocol ip permit

  ppp multilink

  dialer load-threshold 1