Every office has moments when a phone should not ring: a doctor with a patient, a manager in a board meeting, an accountant closing the books. Do not disturb (DND) on an office phone system handles this. One code on the desk phone silences the extension, and callers are sent somewhere useful instead of hearing endless ringing. This guide explains how DND works on an IP PBX, how to set it up so no call is lost, and how it differs from the TRAI DND registry that blocks telemarketing calls.
What DND does on an office phone system
When a user turns on DND, the PBX stops ringing that extension. The caller does not hear a busy tone forever. The PBX treats the extension as unavailable and sends the call to the destination you have set for it, such as voicemail, a colleague, reception or a ring group.
DND is different from call forwarding. Forwarding sends every call to another number, often a mobile. DND simply says “not now” and lets the PBX’s normal fallback rules take over. For a full comparison see call forwarding for business phones.
| Feature | What the caller experiences | Best for |
|---|---|---|
| Do not disturb | Goes to the extension’s fallback, usually voicemail or a colleague | Meetings, consultations, focused work |
| Call forwarding | Rings another number, often a mobile | Working away from the desk |
| Follow me | Rings the desk, then other numbers in turn | Staff who move around the building |
| Time-based routing | Different handling after office hours | The whole company, not one person |
How DND works in Voxdial IP PBX
In Voxdial IP PBX, DND is one of the built-in feature codes. A user dials the DND code from their desk phone to switch it on or off, with no admin login needed.
The administrator controls the code from the Feature Codes page:
- Enable or disable it: each feature code has an Enabled switch, so you can turn DND off across the system if your policy does not allow it.
- Change the code: tick Customize and type your own code, using digits and the * and # keys. Untick it to go back to the default.
- No clashes: if the new code is already used by another feature, the PBX rejects it.
Changes on the Feature Codes page take effect as soon as you make them. Print the final list of codes on a small card for each desk; the PBX feature codes guide shows how to roll codes out to staff.
Set a fallback for every extension
DND is only safe if every extension knows where its calls should go when it is not answered. In Voxdial each extension has a ring time and a destination for unanswered calls. Set that destination before you tell staff about DND.
Common choices:
- Voicemail: the caller leaves a message, and with voicemail to email the user sees it as soon as the meeting ends.
- A colleague or assistant: a doctor’s calls go to the nurse station, a manager’s calls go to their assistant.
- Reception or a ring group: someone always answers, and can take a message or transfer the caller.
If an extension has no fallback, a DND call has nowhere sensible to go. Checking this once for every extension avoids lost calls later.
Good habits for DND in an office
DND causes trouble when people forget it is on. A few simple habits prevent that:
- Use busy lamp field keys. Reception can see on their IP phone who is already on a call before transferring one. See busy lamp field (BLF) for how BLF keys work.
- Turn it off at the end of the meeting. Make this part of the routine, just like unmuting.
- Keep key roles off DND. Reception, the help desk and emergency contacts should not use DND at all. If needed, disable the code for them or cover them with a ring group.
- Use time-based routing for the whole office. If the problem is after-hours calls, do not ask everyone to press DND. Use time-based call routing to send all calls to the night IVR or voicemail.
- Keep call waiting in mind. In Voxdial, call waiting can be turned on or off per extension. A user who finds a second call distracting may only need call waiting off, not DND.
DND for call centre agents
In a contact centre, agents rarely use phone DND. If an agent silences the phone, queue calls stop reaching them but the supervisor cannot see why.
Voxdial Contact Center handles this with break reasons instead. Agents pick a reason such as lunch, training or a team meeting, and the wallboard and reports show who is on break and for how long. Queue calls go to the next free agent, and the time is recorded fairly. See call centre agent status and break codes for how to set up the list.
Office DND vs TRAI DND
People in India often mean something else by “DND”: the National Customer Preference Register run by TRAI, which lets mobile users block promotional calls and SMS. You register by sending a message or calling 1909, or through the TRAI DND app.
| Office phone DND | TRAI DND | |
|---|---|---|
| What it controls | Whether your desk phone rings | Which commercial calls and SMS reach your mobile |
| Who sets it | The user, with a feature code | The mobile subscriber, through their operator |
| Where it works | Inside your company PBX | On your mobile connection |
For a business, TRAI DND matters when you make outbound calls. Customers who have opted out of promotional calls should not receive them, and promotional calling has its own number series and rules. Service calls to your own customers, such as a delivery update or an appointment reminder, follow different rules from sales calls. If spam calls are your problem, read how to block spam calls on a business phone.
Want DND, fallbacks and BLF set up properly across your office? Talk to BitVoice.
FAQs
What happens to a call when DND is on?
The extension does not ring. The PBX sends the call to the extension’s fallback destination, usually voicemail, a colleague or reception.
How do I turn on DND on my office phone?
Dial the DND feature code from your desk phone. Your administrator can show you the code, and can change or disable it on the Feature Codes page in Voxdial.
Can reception see that I am on DND?
Reception can see on busy lamp field keys whether your line is in use. Tell reception when you switch DND on, or ask them to check the fallback before transferring.
Is office phone DND the same as TRAI DND?
No. Office DND stops your desk phone ringing. TRAI DND, set by calling or messaging 1909, blocks promotional calls and SMS to your mobile number.
