Please be aware DISA can be used by hackers to get into your switch....
Direct Inward System Access allows an incoming caller to dial into a Meridian system from an external number, and dial numbers as if the call was being made from an extension.
When the call terminates on the Meridian the system can prompt for passwords before any call can be made. It may also be programmed to accept Authorisation codes allowing different levels of service to individual users. It is recommended that security is set up correctly for the Direct Inward System Access (DISA) Facility
Feature Implementation
The incoming routes and trunks for this facility are set up By contacting BT and arranging for an engineer to program your Meridian.
Changes to the Direct Inward System Access security set-up can be configured by the user in LD 24
LD 24
Direct Inward System Access data block
REQ CHG Change
TYPE DIS Direct Inward System Access data block
CUST X Customer Number (0 – 99)
DN XXXX Direct Inward System Access Directory number
SCOD YYYY Security Password for this Access
AUTR (NO)/YES Authorisation code if required
TGAR xx Trunk Group Access Restriction
NCOS xx Network Class of Service
CLS UNR/TLD/FRE2 etc Class of service restriction
Carriage return until you get back to the REQ prompt
Feature operation
To dial into the system from the public network
1 Dial the DISA number. You hear a dial tone.
2 Dial the security code, if required.
3 Dial the Authorisation Code, if required.
You are now connected to the system as if you are on a extension on the Meridian.