FR 3181 then IB 5092 at Barcelona
Rome → Barcelona → Porto
Timetable, Barcelona time
15:05FR 3181 from Rome at the gate
13:00IB 5092 to Porto leaves the gate
21 h 55 apart on the timetable, overnight
IB 5092 leaves 21 h 55 after FR 3181 arrives on the timetable: more than half a day, so not a connection we count.