User Story

As a business owner, when a call is placed to a hunt group and all members have been tried but no one answers, I want to give callers an alternative to simply dropping the call, such as:

• prompting callers to leave a voicemail
• forwarding callers to selected extensions

This is needed to improve customer satisfaction and to avoid losing potential new leads when no employees are available.

Examples of Use

1. Small legal firm, after-hours trickle. On 2026-03-12 at 17:45, a prospective client calls the "New Clients" hunt group of "Meridian Legal LLC". All three attorneys are already on calls. The system cycles through all members with no answer. Without overflow configured, the caller hears silence and the call drops. With the new overflow feature, the administrator has set the action to Redirect to extension's voicemail (extension 201 — the shared "New Client Intake" mailbox) and enabled a pre-action prompt: "We're sorry we missed you. Please leave your name, number, and a brief description of your matter and we'll call you back within one business day." The caller hears the prompt, then is transferred to voicemail. The firm loses no lead.
2. IT support desk, busy peak hour. On 2026-04-08 at 10:15, a technician calls the "IT Helpdesk" hunt group of "Brightstone Corp" (10 agents). All agents are occupied. The system exhausts all hunt members over 60 seconds. The administrator has configured overflow to Redirect to extension 305, which is a second-tier on-call engineer's direct line. A pre-action prompt plays: "All first-line agents are busy. We are transferring you to a senior engineer." The caller is transferred live, avoiding silent disconnection.

Business Model

Cloud PBX

Current Solution

Hunt groups today silently disconnect the caller when every member in the group has been tried and no one answered. This results in lost customers, missed sales opportunities, and negative caller experience.

Current workaround used by administrators:

1. Administrator creates a phantom/dummy extension (e.g., ext 299 "Overflow Mailbox") in PortaSwitch.
2. The dummy extension is configured with Call Forward Unconditional to another real extension or with enabled Voicemail.
3. The dummy extension is added as the last member of the hunt group.
4. When the hunt group exhausts real agents, it rings the dummy extension, which immediately forwards the call onward.

Pain points of the workaround:

• Requires creating and maintaining an extra extension per hunt group that uses overflow — costly in multi-tenant or large deployments.
• The dummy extension occupies a license slot on some tiers.
• If the dummy extension's forward target changes (e.g., the voicemail number changes), the administrator must update it separately — it is not discoverable from the hunt group configuration screen.
• No pre-action announcement is possible without additional IVR setup.
• Calls dispatched to hunt groups by auto-attendants do not have a failover option (i.e. if such calls are not answered by hunt group members, callers simply get disconnected)
• Audits and troubleshooting are more complex because the overflow intent is hidden inside an unrelated extension's forward configuration.

Stakeholders and Their Benefits

• Business Administrator — Configures overflow directly on the hunt group in a single screen; eliminates dummy extension maintenance; reduces setup time per hunt group.
• End Caller — Hears an announcement; reaches voicemail or a live person instead of being disconnected.
• Business Owner / Sales Manager — Recovers missed calls from prospects; no revenue leaks from unanswered hunt group calls.
• Support/Helpdesk Manager — Can redirect overflow to an on-call engineer or a general voicemail box without complex IVR configuration.
• PortaOne Reseller / ITSP — Competitive feature parity with 3CX, Cisco CUCM, Avaya IP Office, and Webex Calling, which all natively support hunt group or ring group overflow destinations with optional pre-action announcements.

Use Cases

Use Case #1: Configure Hunt Group Overflow Actions

Preconditions:

• Customer "Meridian Legal LLC" has an active account in PortaSwitch.
• Hunt Group "New Client Intake" exists with 3 members: extensions 101, 102, 103; hunting strategy: Sequential; ring time per member: 20 s.
• Extension 201 ("Shared Intake Voicemail") exists and has voicemail enabled.
• Extension 305 exists and is registered.
• Administrator "laura.smith@meridianlegal.com" has access to the custom Customer self-care portal (e.g. CloudPBX portal).

Role: Business Administrator (Laura Smith), End Caller (David Nguyen), PortaSwitch

Use scenario #1.1: Configure overflow to extension's voicemail with no pre-action prompt

• Laura logs into the customer self-care portal.
• She opens "New Client Intake" and defines the Overflow action:
  • Redirect to extension's voicemail (other available actions are Disconnect and Redirect to extension)
  • Extension 201
• She leaves Play before action disabled.

Use scenario #1.2: Configure overflow to a different live extension with no pre-action prompt (alternative to #1.1)

• Laura configures the Overflow action similar to #1.1, but selects to redirect calls to extension 305.

Use scenario #1.3: Configure overflow to Disconnect (default action, alternative to #1.1)

• Laura configures the Overflow action as Disconnect
• Laura sets Play before action = Custom prompt and uploads a file ("overflow_legal.wav")

Use scenario #1.4: Call flows depending on the overflow actions

• continued after #1.1-1.3
• Caller "David Nguyen" is calling from +1-416-555-0188.
• PortaSwitch routes the call to Hunt Group "New Client Intake".
• Extensions 101, 102, 103 are all registered but currently busy on other calls (no call waiting capacity).

Wireframes

Non-functional Requirements

N/A

Peculiarities

• In SIP-14784, we introduced a new enable_legacy_huntgroup_behavior option that returns pre-FR-515 behavior for hunt groups. During the solution design, consider if it's worth dropping that option after we implement the changes described in this BRS

Performance / Clustering, Geo Redundancy/ Dual-Version, Porter / Call Control API / ESPF / Monitoring

• The solution must be supported for the standalone mode and dual-version modes