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Set Up DISA

DISA (Direct Inward System Access) lets an outside caller dial in, authenticate with a PIN, and then dial out as if they were an internal extension. Useful for "calling card" scenarios — letting employees dial out using the company's outbound CID and trunks from their personal cell.

Security risk

DISA is a favorite target for fraud. ALWAYS:

  • Use a strong PIN (8+ digits, NOT 1234567).
  • Restrict outbound routes available via DISA (use Class of Service or carefully chosen Routing Outbound Routes setting).
  • Monitor CDR for unusual DISA activity.
  • Never expose DISA on a Misc App with no PIN.

Before You Start

  • A strong PIN is chosen (8+ digits, random).
  • The destination that triggers DISA is decided (e.g. an IVR option, a Misc App feature code, or a dedicated DID).
  • Outbound routes the DISA user is allowed to use are identified.

Steps

  1. Go to Trunk Attributes → DISA.
  2. Click + Add DISA.
  3. Fill in:
    • DISA name — e.g. Manager DISA.
    • PIN — 8+ digits. Multiple PINs can be added comma-separated for per-user tracking.
    • Response Timeout — how long to wait for the user to start dialing after auth. Default 10.
    • Digit Timeout — how long to wait between digits. Default 5.
    • Require Confirmation — No.
    • CallerID — what CID to set on outbound calls placed via this DISA. e.g. "Co Main" <2075551234>.
    • Context — usually from-internal. DO NOT set to from-pstn — that defeats the point.
    • Allow Hangup — No.
  4. Click Submit.
  5. Click Apply Config.

Use It

The DISA is now a destination. Point an Inbound Route, IVR option, or Misc App at it.

A typical setup: Inbound Route → IVR → option 9 (hidden, not announced) → DISA. The user calls the main number, presses 9, gets the DISA tone, enters PIN, then dials.

Verify

Call the entry point (DID + IVR option, or feature code). After the IVR, you should hear a brief silence then a dial tone. Enter the PIN, then dial a number. The call should go out the configured outbound CID.

Common Issues

  • No dial tone after DISA enters. Context is wrong (try from-internal) or the user isn't allowed to dial out (Class of Service / outbound route restrictions).
  • PIN accepted but call fails. Outbound route requires its own password OR the route doesn't allow this CID.
  • Fraud detected. Disable DISA immediately, change the PIN, audit CDR. Consider limiting DISA to specific outbound routes (local-only, not international).
  • Hidden IVR option exposed. Don't announce the digit in the IVR greeting. Keep it secret + use a strong PIN.