SolutionPossible ProblemStatus Line Condition
A local or remote router is
misconfigured.
Keepalives are not being sent by
the remote router.
A leased-line or other carrier
service problem has occurred
(noisy line or misconfigured or
failed switch).
A timing problem has occurred on
the cable.
A local or remote CSU/DSU has
failed.
Router hardware (local or remote)
has failed.
Serial x is up, line protocol is down
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS XE
Everest 16.5
OL-14127-17 327
Troubleshooting the Serial SPAs
Serial Lines: show interfaces serial Status Line Conditions