use this command in order to up your E1 interface then you configure your modems.
conf t
int controller e1 0
framing NO-CRC4
clock source line primary
ds0-group 0 timeslots 1-15,17-31 type r2-digital
cas-custom 0
in order to config your modems you should use these commands.
conf t
line 1 120
modem Dialin
modem autoconfigure type mica
autocommand ppp
transport preferred none
transport input all
transport output none
autoselect during-login
autoselect ppp
just this
its very simple but compelecative