# Camp on to a Busy Extension

When you dial a colleague and reach a busy signal, Busy Camp-on lets you hold your place instead of dialing again and again. You register a reservation against the busy extension, hang up, and the phone system (the PBX, short for Private Branch Exchange) watches for that extension to become free. The moment it does, the system rings you back and bridges the two of you together.

## What to know before you use it

- Busy Camp-on works only for internal calls between two extensions. It does not apply to inbound or outbound external calls.
- A reservation stays active for **3600** seconds (one hour). If the extension you are waiting on is still unavailable after that window, the system drops the request and will not call you back.
- Each extension can hold up to **10** Busy Camp-on reservations at once. When an eleventh is added, the system discards the oldest one to make room.

:::caution
Busy Camp-on has to be enabled in the web portal before anyone can use it. If the feature code is turned off there, dialing it does nothing and no callback is scheduled, so confirm the feature is enabled before relying on it.
:::

## How it works

Suppose extension 1000 calls extension 2000, but extension 2000 is already on a call. Rather than keep retrying, the person at 1000 can register a camp-on and let the system handle the reconnection.

1. From extension 1000, dial the feature code (a short star-key code that triggers a phone-system function) followed by the target extension number. The default is `*79`, so you would dial `*792000` to camp on to extension 2000. The system plays the prompt "The Busy Camp-on has been enabled" and ends the call automatically.

   :::tip
   `*79` is the default feature code for Busy Camp-on. You can change the code, or turn the feature on and off entirely, from the PBX web portal under **Call Features > Feature Code > Busy Camp-on > Enable Busy Camp-on**.
   :::

2. As soon as extension 2000 hangs up and becomes available, the system rings extension 1000. The incoming call shows a caller ID of **Busy Camp-on** followed by the name and number of the extension being reached. After answering, the person at 1000 hears the prompt "This call is connected via Busy Camp-on feature."

3. The system then places the call to extension 2000. Once extension 2000 answers, the two extensions are connected.