Here is a very basic configuration for a point-to-point T1, and assume that all 24 timeslots are used:
1841:
interface serial 0/0/0
ip address 192.168.255.254 255.255.255.252
no shutdown
service-module T1 clock source internal
!
ip route <remote site network> <mask> 192.168.255.253
ip route 0.0.0.0 0.0.0.0 <ip of local firewall>
2611:
interface serial 0/0
ip address 192.168.255.253 255.255.255.252
no shutdown
!
ip route 0.0.0.0 0.0.0.0 192.168.255.254
Done.
