This read-only octet string holds the E.164 address of the destination end of the current ISDN connection, the called-party number for this active call, complementing lportISDNSourceAddr's originating-party number. An admin checks this to confirm the call landed on the intended destination, particularly useful when troubleshooting a backup ISDN dial plan that might have multiple possible destination numbers configured. For example, if an ISDN backup call was supposed to reach a specific central-site number but lportISDNDestAddr shows it actually connected to a different number, that points to a dial-plan misconfiguration.