I suggest this document from Cisco to understand the configuration in more depth: https://www.cisco.com/c/en/us/td/docs…
The applicable configuration:
controller Cellular 1
description AT&T
lte sim data-profile 1 attach-profile 1
no lte gps enable
lte modem link-recovery rssi onset-threshold -110
lte modem link-recovery monitor-timer 20
lte modem link-recovery wait-timer 10
lte modem link-recovery debounce-count 6
interface Cellular1/0
ip address negotiated
encapsulation slip
load-interval 30
dialer in-band
dialer string lte
dialer-group 1
no peer default ip address
routing dynamic
dialer-list 1 protocol ip permit
ip route 0.0.0.0 0.0.0.0 Cellular1/0
