This selects which Data Link Connection Management Interface (DLCMI) signaling standard, disabled, LMI revision 1, ANSI T1.617 Annex D, ITU/CCITT Q.933 Annex A, or autodetect, is active on this frame relay logical port. The DLCMI standard in use on this specific logical port determines which reserved DLCI value carries the keepalive/status-polling exchange with the far end, so a mismatch here against what the connected router or switch expects will typically show the PVC as down for signaling purposes even while the underlying physical circuit and DLCI itself are working fine. A router connected to this port that only supports the original LMI Gang-of-Four convention would need this object set to lmiRev1 rather than the newer ANSI or ITU standards, or its DLCMI status polling would go unanswered.