How to stop agents dialing outside a campaign with Phone Context

In a call center you usually want agents dialing through the dialer, not punching numbers into their handset to make calls on their own. There is a clean trick for that, and it lives in one field on the phone entry: Phone Context. Point it at a dialplan context that does not exist, and the phone simply cannot place outbound calls by itself. Agents can still take and make calls through the VICIdial screen, but the handset on its own goes nowhere.

What Phone Context is

Phone Context is the Dialplan context a phone uses to dial out. A context is a named block of routing rules inside Asterisk. When the device dials a number on its own, the call enters this context and the rules there decide where it goes. The default value is literally default, which routes calls normally. The lock works by pointing Phone Context somewhere that has no rules at all.

The agent-nodial trick

Set Phone Context to a context name that does not exist on the server, something like agent-nodial. Because no such context is defined, any call the phone tries to originate by itself has nowhere to go and fails immediately. The agent picks up the handset, dials a number, and gets dead air or a fast busy. Meanwhile the VICIdial screen still works perfectly, because dialer-originated calls do not rely on the phone's own dial-out context.

flowchart TD
  A[Agent dials on handset] --> B[Call enters Phone Context]
  B --> C{Context exists?}
  C -->|Yes default| D[Call routes out normally]
  C -->|No agent-nodial| E[No rules found]
  E --> F[Call fails dead end]

The name agent-nodial is just a convention. Any string that is not a real context works. The point is that it must not match anything defined on the box, so there is no path for the call.

How to set it

1. Open the phone entry for the agent's device.
2. Find the Phone Context field, normally set to default.
3. Change it to agent-nodial and save.
4. Test by trying to dial a number directly from the handset; it should fail.

Do this on every agent Extension you want locked down, whether the device is a desk phone or a SIP (Session Initiation Protocol) softphone. Leave supervisor or test phones on default if those people legitimately need to dial out by hand.

What it does not block

This locks the phone's own outbound dialing only. It does not affect inbound calls and it does not stop calls placed through the VICIdial application, because those run through a different path. It also does not touch what context the phone uses to receive calls; that is a separate field. So agents keep working normally inside the dialer while losing the ability to make freelance calls from the device.

Phone Context is easy to confuse with the field next to it, Exten Context, which governs the context the phone primarily operates in rather than dials out with. If you want the distinction spelled out, read what the Phone Context field does for the dial-out side and the Exten Context field for the receive side. The VICIdial phones guide covers how all of these fit together on one entry.

Locking down dialing is one of those settings you want applied consistently across every agent phone, not done one at a time and forgotten. A managed VICIdial host can bake sane policies into provisioning so you are not editing contexts by hand. See VICIfast pricing to see what comes set up for you.