interface Loopback1
 ip address 172.16.31.1 255.255.255.255
interface Loopback2
 ip address 172.16.31.2 255.255.255.255
bstun peer-name 172.16.31.2
bstun protocol-group 1 async-generic
interface Serial0
 physical-layer async
 encapsulation bstun
 async mode dedicated
 bstun group 1
 bstun route all tcp 172.16.31.2
 asp role primary
 asp addr-offset 0
interface Serial1
 physical-layer async
 encapsulation bstun
 async mode dedicated
 bstun group 1
 bstun route all tcp 172.16.31.1
 asp role primary
 asp addr-offset 0