How to set the External Extension on a Remote Agent

Setting the External Extension on a Remote agent record is a three-step task: figure out the right number, type it into the field correctly, then test it from the dialer before the agent goes live. This post walks through each step. If you are not sure what the External Extension field is for at all, see the companion post on what the field does — this one focuses on the how.

Step 1 — Determine the correct dialplan number

The External Extension is the exact digit string that Asterisk needs to route the call to the agent's phone. Before you touch the remote agent form, answer these two questions:

1. Where is the phone? If it is a SIP extension registered directly to your VICIdial server, you probably just need the 3–5 digit extension number. If it is an outside number (cell phone, landline, off-site PBX), you need the full E.164-style string that your SIP trunk expects.
2. Does your dialplan require an access code? Many Asterisk setups use a leading digit (commonly 9) to distinguish external calls from internal extensions. If yours does, that digit must be part of the External Extension value.

If you are unsure about the Dialplan structure, ask whoever manages your Asterisk config. The wrong prefix means the call attempt hits a dead end with no error visible to the agent.

Step 2 — Enter the value on the remote agent record

Log into the VICIdial admin panel, go to Remote Agents, and click the Modify link on the record you want to edit (or use Add New Remote Agents for a new one).

1. Locate the External Extension field.
2. Type the complete digit string — digits only, no spaces, dashes, parentheses, or letters. The form rejects non-digit characters.
3. Check the Extension Group field. If it is set to anything other than NONE, the External Extension field will be ignored by the system regardless of what you type. Set Extension Group to NONE if you want the External Extension to take effect.
4. Save the record.

flowchart TD
    A[Open Remote Agent modify screen] --> B[Enter digits-only number in External Extension]
    B --> C{Extension Group = NONE?}
    C -- Yes --> D[External Extension will be used]
    C -- No --> E[External Extension is ignored — update Extension Group or set to NONE]
    D --> F[Save record]
    E --> F
    F --> G[Test by dialing number from a dialer phone]
    G --> H{Call reaches correct destination?}
    H -- Yes --> I[Set Status to ACTIVE]
    H -- No --> J[Fix the number and retest]

Step 3 — Test the number before activating

Pick up a SIP peer or softphone that is registered to your VICIdial Asterisk server and manually dial the exact string you entered in the External Extension field. You are checking that the call routes correctly through your Asterisk dialplan — not just that the phone number works in general.

If the call connects cleanly, the value is correct. Set the remote agent Status to ACTIVE and the dialer will begin sending calls. If the call fails, adjust the number — add or remove the access prefix — and retest before activating.

Once live, the Agent API gives you programmatic control over calls sent to this remote agent — hangup, transfer, and disposition are all available if your integration needs them.

For a full breakdown of every field on the remote agent modify screen, the VICIdial remote agents guide covers all of them. And if you want to compare this setup against logging in with a standard agent account, remote agent vs standard agent explains the trade-offs.

Running VICIdial on a managed server removes a lot of the dialplan guesswork. See VICIfast plans if you would rather spend time on your campaign than on server configuration.