This counter tracks associations that transitioned directly from CLOSED to ESTABLISHED because a remote peer initiated the setup. This tells the admin the device is acting as the server side for that association, useful for telling apart, on a box that plays both roles, which peers are calling in versus which it is calling out to. A signaling gateway whose ceSctpPassiveEstab climbs steadily while ceSctpActiveEstab stays at zero is purely receiving inbound SIGTRAN connections, never originating them.