load balancing

[nat]

ciao a tutti,avrei bisogno di capire,se è possibile, come configurare due router 827 con due contratti telecom interbusiness con punto punto e lan differenti per i due contratti, in modo tale chè se una linea va giù,possa subentrare l'altra,posto la configurazione di uno dei due router

service timestamps log datetime localtime
service password-encryption
service udp-small-servers
username ciao password ciao
no service tcp-small-servers
!

hostname t-
!

enable secret 5
!
ip subnet-zero
no ip source-route
ip domain-name interbusiness.it
ip name-server 151.99.125.2
!
!
!
!

no ip dhcp pool CLIENT

no ip dhcp excluded-address 10.10.10.1

no access-list 23
!
!
!

interface Ethernet0

ip address 80.80.80.9 255.255.255.248

ip address 192.168.1.1 255.255.255.0 secondary

ip nat inside

ip access-group 102 out
no shut
!
!

interface ATM0
no ip address
no atm ilmi-keepalive
dsl operating-mode auto
no shut
!
!

interface ATM0.1 point-to-point
ip address 10.10.10.10 255.255.255.252
ip nat outside

ip access-group 103 out
ip access-group 104 in
no ip directed-broadcast
bandwidth 128
pvc 8/35
oam-pvc manage 10
oam retry 5 5 1
encapsulation aal5snap
no shut
!
!

ip route 0.0.0.0 0.0.0.0 Atm0.1

ip route 80.80.80.0 255.255.255.0 Atm0.1
!
!

logging buffered
ip classless
!

ip nat pool net-ibs 80.80.80.10 80.80.80.10 netmask 255.255.255.248
ip nat inside source list 1 pool net-ibs overload
!
!

access-list 1 permit 192.168.1.0 0.0.0.255





access-list 102 deny ip 80.80.80.8 0.0.0.7 any
access-list 102 permit tcp any 80.80.80.8 0.0.0.7 established
access-list 102 permit ip any 80.80.80.8 0.0.0.7

access-list 102 permit ip any 192.168.1.0 0.0.0.255


access-list 103 permit ip 80.80.80.8 0.0.0.7 any
access-list 104 deny tcp any any eq 2065
access-list 104 permit ip any any

!
!
line con 0
login local

line vty 0 4

gli host resteranno sempre gli stessi con i soliti indirizzi privati.
nel secondo router quali sono i parametri da modificare?
un grazie anticipato.