NEC ASPILA EX Feature Manual page 178

Operation
164 Features
Direct Inward Dialing (DID) or Direct Dial In (DDI)
Direct Inward System Access (DISA)
DISA also allows outside callers to dial system extensions directly.
Off Hook Signaling
The Off Hook Signaling provide DID calls with signaling options. Refer to this feature for the
specifics.
Programmable Function Keys
To simplify answering DID calls, assign function keys as line keys for the DID trunks.
Station Message Detail Recording
SMDR can print trunk port names or received dialed number for ANI/DNIS or DID trunks. If
enabled, DNIS digits can be printed on the SMDR reports instead of the trunk name.
DID calls ring extensions like normal trunk calls.
Aspila EX Software Manual