Hunt groups exist because a business DID often should not ring a single desk. The inbound call hits a group object. The PBX then rings members according to a hunt algorithm until someone answers, the group timeout fires, or the call overflows. There is no "you are number 3 in line" unless the platform has already placed the caller in a queue. Hunting is ringing, not waiting in a buffer.
Sequential, simultaneous, longest-idle, circular
| Algorithm | Who rings | What it optimizes | Watch-outs |
|---|---|---|---|
| Sequential (linear, regular hunt) | Member 1, then 2, then 3, each for a ring timeout | A preferred first responder (front desk, then backup) | Member 1 gets almost every call. Slow if early members never answer. |
| Simultaneous (ring all, parallel) | Every available member at once. First answer wins. | Minimum time-to-answer for a small team | Noisy. Does not scale. Ties go to whoever picks up first, not the least busy. |
| Longest-idle | The member whose last answered call is oldest (among those logged in / not DND) | Rough load balancing without a full ACD | Needs accurate idle timers. A member who never answers can look "idle" forever unless skipped. |
| Circular (round-robin) | Next member after the one who received the previous offer or answer, wrapping the list | Share offers around the team | Not the same as longest-idle. A round-robin offer can still land on someone already on a call, depending on skip-busy rules. |
Hunt groups vs ring groups
In classic TDM PBX language, a hunt group tries members in order (a hunt). A ring group rings them all. Many VoIP products use "ring group" as the feature name and then offer sequential and simultaneous as modes of the same object. Treat the algorithm as the real contract. The label is marketing-adjacent vocabulary, not a standard.
- Members are usually extensions or users, not arbitrary PSTN numbers. Forwarding a member to a cell is call forwarding on that member, which can delay the rest of the hunt.
- Logged-out / DND members should be skipped. If they are not, sequential hunts waste the full ring timeout.
- A hunt group is a finite ring cycle. When the cycle ends, the call must go somewhere: voicemail, IVR retry, overflow group, or a queue.
Hunt groups vs call queues
| Hunt / ring group | Call queue (ACD) | |
|---|---|---|
| Caller state while waiting | Ringing (or early media). No position. | Parked in a queue with wait treatment (MOH, announcements). |
| When all members are busy | Busy, next member, or overflow after the hunt timeout. | Stay in queue until an agent is free, or overflow on max wait / max length. |
| Reporting | Answered / abandoned / overflow. Limited SLA language. | Wait time, AHT, service level, abandon rate, position. |
| Scale | Fits a handful of people who can hear a phone ring. | Fits a contact center where demand exceeds simultaneous agents. |
A common pattern is an IVR digit that sends the caller to a queue (when wait treatment is needed), which then offers the call to agents by skill. Relying on a simultaneous ring group alone for a busy inbound line produces missed calls.
How a hunt is evaluated
- Call arrives for the group number or via an IVR transfer.
- The PBX builds the candidate list: members in the group who are registered, not DND, and (if configured) not already in a call.
- It offers the call according to the algorithm and per-member ring time.
- On answer, other offers are cancelled (especially important in simultaneous mode).
- On group timeout or empty candidate list, apply the no-answer destination.
Identity, devices, and forwarding
The caller still presents ANI / caller ID to the answering member. Members ringing on WebRTC apps and desk phones are on-net. Members who CFU to a mobile add a PSTN hop and may show a different outbound identity. E911 is per device, not per hunt group: answering a customer call on a cell does not register that cell as the office dispatchable location.