A conference call system lets three or more people talk on one call, whether they sit in the next cabin, in a branch office or on a mobile phone in another city. Most offices already have one built into their phone system, but few use it well. This guide explains the three kinds of conference call on an IP PBX, when to use each, and how to set them up so meetings start on time and sound clear.
Three ways to run a conference call
There is no single “conference” feature. A modern phone system offers three, and each suits a different situation.
| Type | How it starts | Best for |
|---|---|---|
| Ad-hoc conference on a phone | You are on a call and add another person from your desk phone | Quick three or four person calls that grow out of a normal call |
| Conference handoff by an operator or agent | The operator or agent joins the caller with a colleague, then leaves | Introductions, escalations and complaints |
| Conference room (bridge) | Everyone dials one internal number at an agreed time | Planned meetings with several people and branches |
Ad-hoc conference from the desk phone
This is the simplest kind. You are already talking to someone, you press the conference key, dial a third person and join everyone together. The phone itself mixes the audio, so the size of the call depends on the handset. The BitVoice B301 and B303 IP phones support 6-way conferencing, which covers most quick discussions between a manager, a customer and two or three colleagues.
Use ad-hoc conferences when a call needs one more voice, such as bringing in accounts while you talk to a customer about an invoice.
Conference handoff from the operator or agent console
At a reception desk or in a call centre, the most useful conference is short. The operator brings a colleague into the caller’s call, introduces both sides and steps out. In the Voxdial operator console, once the conference is running the operator can leave so the other two keep talking, hang up the second party, or end the conference for everyone. Agents in Voxdial Contact Center have conference in the agent console too, next to hold, park and transfer.
This avoids the caller repeating their story. For when to use a conference instead of a transfer, read attended vs blind transfer.
Conference rooms for planned meetings
For a weekly review with three branches, an ad-hoc call is hard to manage: one person has to dial everyone, and if their phone drops, the meeting ends. A conference room on the PBX works like a meeting room you dial into. It has its own internal number, everyone calls it at the agreed time, and the call does not depend on any one handset.
Voxdial IP PBX includes conference rooms for meetings alongside paging, intercom and call routing. Because the room is just a number on the PBX, staff can reach it from desk phones, softphones and analog phones on gateways. Branches connected to the same system dial it as an internal call, so there is no outside call charge.
How to set up conference calling in an office
1. Give conference rooms clear numbers
Pick a block of internal numbers for conference rooms and keep it separate from extensions and feature codes, for example one room per department. Planning number ranges is covered in our guide to designing a PBX dial plan.
2. Decide who outside callers can reach
If customers or partners need to join, they need a way in from outside. A common pattern is an IVR option or a direct number that leads to the conference room. Keep this limited to the rooms that need it, and protect them where your system allows, so strangers cannot listen in.
3. Check the phone lines
Every outside participant uses one channel on your SIP trunk or PRI line for the whole meeting. A meeting with eight outside callers needs eight free channels, on top of normal office calls. Check your trunk capacity before a large call, and read SIP trunks in India if you need more channels.
4. Use HD voice where you can
Conference calls magnify poor audio, because every noisy line is heard by everyone. Use wideband G.722 on internal phones where possible and ask people to mute when they are not speaking. Our guide to VoIP codecs explains which codec to use where.
5. Train people on the conference key
The ad-hoc conference is only useful if staff know it exists. Show each team how to add a person, how to drop the last person added, and how to leave a call without ending it for others.
Good habits for clearer conference calls
- Use a headset or handset rather than a speakerphone in an open office.
- Mute when you are not talking, especially on mobile phones in traffic.
- Start with names: ask each person to say who they are when they join.
- Keep a dedicated room number for each regular meeting, so the invite never changes.
- End the call from the organiser’s side so nobody is left in an empty room.
Conference calls or video meetings?
Video tools are useful for presentations, but many Indian businesses still run daily coordination on voice: plant heads on the shop floor, field sales on mobiles, and branch managers who join from a desk phone. A PBX conference works on any phone, does not need an app or a laptop, and uses the same lines your office already pays for. For most daily calls, voice is faster to join and more reliable on weak networks.
Want conference rooms set up for your branches and teams? Talk to BitVoice.
FAQs
What is a conference call system?
It is the part of a phone system that joins three or more people on one call, either from a desk phone, through an operator or agent console, or in a conference room that everyone dials into.
How many people can join an ad-hoc conference on an IP phone?
It depends on the phone. The BitVoice B301 and B303 IP phones support 6-way conferencing from the handset.
What is the difference between an ad-hoc conference and a conference bridge?
An ad-hoc conference is built from a live call on one phone. A conference bridge or room is a number on the PBX that everyone dials at an agreed time, so the meeting does not depend on one handset.
Do outside callers use phone lines during a conference?
Yes. Each outside participant uses one channel on your SIP trunk or PRI line for the length of the call, so check capacity before large meetings.
