This read-only Integer32 (0..2147483647) is the Call Reference value assigned to a specific SVC or SPVC call on this interface. An administrator uses this identifier to correlate the many other per-call attributes in this table (addresses, traffic parameters, delay/loss bounds) with one specific active call, and to cross-reference it against the partner interface's call reference. For example, an engineer troubleshooting a failed call matches cwspCallCallRef on the ingress interface to cwspCallOtherIntfCallRef reported by the egress interface to confirm both sides agree they are looking at the same call leg.