This read-only value reports the DLCI (if this is a frame relay circuit) or the concatenated VPI/VCI (if this is an ATM circuit) at this node's ingress port for the corresponding multipoint circuit's leaf. This identifies the specific virtual channel identifier used at the local ingress point, which combined with cktLeafSrcIfIndex fully specifies where and on what logical channel this leaf's traffic arrives at this node. An engineer cross-referencing switch configuration against live circuit tables to confirm a leaf is using its expected DLCI would check cktLeafSrcDlci against the provisioned DLCI value.