SIP PBX Dial Actions

Overview

The Dial resource creates, controls, and waits on outbound dial sessions.

Operations

Operation	Purpose	Output branches
Make Call	Create a new outbound dial.	Result, plus Unavailable for Mode = Extension
Break	Stop an active dial.	Result
Wait Event	Wait for ringing, progress, answer, reject, fail, or timeout.	Dynamic selection plus fixed terminal branches

Common Concepts

Field	Meaning
dialId	Identifier of the dial session.
legId	Master leg returned when the created dial has one immediately available.
stillDialingLegCount	Remaining in-progress attempts after a Wait Event result.

Operation: Make Call

Main Parameters

Parameter	Required	Shown when	Description
Mode	Yes	Always	Trunk, Extension, Direct, or WebSocket.
Trunk Ref	Yes	Mode = Trunk	Public trunk ref used for outbound routing.
Destinations	Yes	Mode = Trunk or Direct	Comma-separated phone numbers or SIP users. Do not include server or auth data here.
SIP Connection	Yes	Mode = Direct	SIP credential used for direct outbound signaling.
Extensions	Yes	Mode = Extension	Comma-separated extension numbers. Calls every matching endpoint across all visible extensions refs in the current workflow scope.
Transport Profile	Yes	Mode = WebSocket	OpenAI Realtime, Gemini Live, or Generic.

Common SIP Dial Options

These options are available for Mode = Trunk, Direct, and Extension.

Option	Description
Call Strategy	All In Parallel or Sequential.
Sequential Attempt Timeout (Seconds)	Timeout per sequential attempt.
Sequential Gap (Seconds)	Delay between sequential attempts.
Caller Number	Outbound caller number override.
Caller Name	Outbound caller display name override.
Custom SIP Headers	Extra SIP headers applied to outbound SIP attempts.

Direct-Only SIP Media Filters

Option	Description
Codecs	Allowed SIP audio codecs for this direct dial. This is an allow-list only, not a priority override. The runtime keeps its built-in codec priority.
DTMF Methods	Allowed DTMF methods for this direct dial: RFC2833, SIP INFO, Inband. This is a filter only, not a priority override.

Extension-Specific Option

Option	Description
Only Free Endpoints	If enabled, only endpoints that are registered and not currently in a live call are targeted.

Trigger-Scoped SIP Media Filters

Mode	Behavior
Trunk	Outbound media filters come from the resolved trunk trigger for the selected Trunk Ref.
Extension	Outbound media filters come from the resolved extensions trigger route for each targeted endpoint.
Direct	Outbound media filters come from the dial action itself through the direct-only Codecs and DTMF Methods options.

WebSocket Parameters

Shared WebSocket Dial Parameters

Parameter	Required	Shown when	Description
WebSocket Start Mode	No	Transport Profile = OpenAI Realtime or Gemini Live	Immediate starts the provider session as soon as the leg is ready. Deferred waits for Attach Voice Agent.

OpenAI Realtime

Parameter	Required	Description
OpenAI API	Yes	OpenAI credential for realtime session setup.
OpenAI Realtime Model	No	Realtime-capable model used for the session.
OpenAI Realtime Voice	No	Voice identifier used by the session.
OpenAI Input Transcription Model	No	Input transcription model for speech-to-text.
OpenAI Instructions	No	Session instructions prompt.
OpenAI Prompt ID	No	Prompt registry ID.
OpenAI Prompt Version	No	Prompt version string.
OpenAI Prompt Variables JSON	No	JSON object with prompt variables.

Gemini Live

Parameter	Required	Description
Gemini API	Yes	Gemini credential for live session setup.
Gemini Live Model	No	Live-capable Gemini model.
Gemini Live Voice	No	Voice identifier used by the session.
Gemini Live API Version	No	API version string.
Gemini Live Instructions	No	Session instructions prompt.

Generic WebSocket

Parameter	Required	Description
WebSocket URL	Yes	Target WebSocket URL.
Generic WebSocket Headers JSON	No	JSON object with outgoing headers.
Generic WebSocket Initial Messages JSON	No	JSON array of messages sent immediately after connect.
Generic Outgoing Audio Event Type	No	Event type used for PBX-to-WebSocket audio.
Generic Outgoing Audio Field	No	Field name used for PBX-to-WebSocket audio payload.
Generic Outgoing Audio Sample Rate	No	Sample rate for PBX-to-WebSocket audio.
Generic Incoming Audio Event Types	No	Comma-separated event types treated as WebSocket-to-PBX audio.
Generic Incoming Audio Field	No	Field name used for WebSocket-to-PBX audio payload.
Generic Incoming Audio Sample Rate	No	Sample rate for WebSocket-to-PBX audio.

For WebSocket behavior and AI orchestration, see AI and WebSocket Legs.

Output

Branch	Shown when	Fields
Result	Always	dialId, optional legId, optional sipPbx.dialId, optional sipPbx.legId
Unavailable	Mode = Extension only	reason, message, extensionNumbers

Operation: Break

Parameters

Parameter	Required	Description
Options -> Dial ID	No	Explicit dial target. If omitted, resolves from item.json.dialId, then item.json.sipPbx.dialId.
Options -> Reason	No	User-defined break reason string.

Output

Branch	Fields
Result	dialId

Operation: Wait Event

Parameters

Parameter	Required	Description
Overall Timeout (Seconds)	No	Maximum total wait time before the action takes the Timeout branch.
Master Leg ID	No	Optional leg retained for the duration of the wait so it does not expire by TTL. Also used as the source of interrupt events for the Interrupted branch.
Interrupt On	No	Optional wait interrupt signals from the master leg. Currently supports DTMF. This interrupts the wait itself, not the dial.
Additional Outputs	No	Enables extra branches: Ringing, Progress, Rejected.
Dial IDs	No	Explicit wait target list. If empty, the node falls back to the current item dial ID.

Output Branches

Branch	When it appears
Ringing	Only if enabled in Additional Outputs
Progress	Only if enabled in Additional Outputs
Rejected	Only if enabled in Additional Outputs
Answered	Always
Interrupted	Always
Timeout	Always
Failed	Always

Output Payload

Field	Meaning
dialId	Dial that produced the event.
legId	Attempt leg associated with the event, when present.
eventType	Dial event type such as ringing, progress, answered, interrupted, rejected, failed, or timeout.
reason	Failure or rejection reason when relevant.
interruptReason	Present on Interrupted, for example call_dtmf or call_ended.
digit	Present on DTMF-based Interrupted.
stillDialingLegCount	Number of attempts still in progress after this event.

Interrupted semantics

dial.wait also uses the shared built-in interruptReason catalog, but only the master-leg subset:

• call_dtmf
• call_ended

Situation	Result
Master leg ends while the wait is active	The action takes Interrupted with interruptReason = "call_ended".
Interrupt On includes DTMF and the master leg receives DTMF	The action takes Interrupted with interruptReason = "call_dtmf" and includes the detected digit. Queued matching DTMF is observed non-destructively, so a later call.wait on the same leg can still see it.
A matching call_ended or DTMF event was already queued on the master leg before dial.wait started	The action can take Interrupted immediately from that queued event. Matching queued call_ended and DTMF events are not consumed by this immediate check.
Interrupt On does not include DTMF and the master leg receives DTMF	The wait ignores that DTMF and consumes it from the master leg event queue. A later call.wait will not see it.
The dial itself reaches answered, failed, or timeout first	The action takes the corresponding dial branch instead.
The master leg is destroyed while dial.wait is active	The action always takes Interrupted with interruptReason = "call_ended", even if Interrupt On is empty or does not include DTMF.

Master-leg ownership note

Master Leg ID affects only the wait itself:

• it keeps the watched leg retained while dial.wait is active
• it can interrupt the wait on call_ended
• it can optionally interrupt the wait on DTMF

It does not stop the dial. If the master leg ends, the dial can continue running unless some other runtime component, such as queue ownership, stops it separately.