DTMF
Keypad input on voice calls, from how digits travel over SIP to collecting them in a flow, forwarding them to a bot and sending them onward. Browse the feature map or configuration finder.
Availability: Next. Entries that depend on an optional feature, a role or a deployment choice name it in their own Availability line.
Features in this family
- Collect keypad digits in a flow
- DTMF transport over SIP (RFC 4733)
- Let a voice agent collect digits
- Select an extension by keypad before the flow starts
- Keypad input in recordings and transcripts
- Review and diagnose keypad input
Collect keypad digits in a flow
A flow step waits for the caller to press keys, stores the digits in a flow variable and branches on completion, abort or exhausted attempts.
For: Application builders
| Level | Where to change it | Owner section |
|---|---|---|
| Flow and node settings | Flow Designer › DTMF Collect node(dtmf_collect, maxDigits, timeoutMs, terminationKey, resultVariable, maxAttempts, prompt.media, dtmfResult) | DTMF collect: gather keypad input |
Read more:
- Reference: Configure the collection
- Set it up: DTMF collect: gather keypad input
- Reference: Interpret the result
- Troubleshoot: Diagnose missing or unexpected keypad input
Related features: DTMF transport over SIP (RFC 4733), Let a voice agent collect digits.
DTMF transport over SIP (RFC 4733)
Digits are carried as RTP telephone events between the carrier, the media relay and the voice service; SIP INFO and in-band tones are not a verified path.
For: Integrators, Deployment operators
| Level | Where to change it | Owner section |
|---|---|---|
| Services and containers | TelSys PJSIP endpoint template(dtmf_mode=rfc4733, telephone-event) | Codecs and DTMF |
Read more:
- Reference: Codecs and DTMF
- Reference: Limits
- Troubleshoot: Diagnose missing or unexpected keypad input
Related features: Voice codecs on SIP calls, Collect keypad digits in a flow.
Let a voice agent collect digits
A voice agent capability shortcut gives the agent a digit-collection tool and guidance rather than a separate keypad step.
For: Application builders
| Level | Where to change it | Owner section |
|---|---|---|
| Flow and node settings | Voice agent › Capabilities › Collect keypad input(collect_digits) | Capability shortcuts and their concrete effects |
Read more:
Related features: Collect keypad digits in a flow.
Select an extension by keypad before the flow starts
When a number uses extensions, the caller keys in a short extension code before the application flow begins, with its own attempt window.
For: Team administrators, Application builders
| Level | Where to change it | Owner section |
|---|---|---|
| Team settings | Base number › Extensions(extensionsEnabled, Extension.code) | Manage base numbers |
Read more:
- Reference: Keep extension selection separate
- Set it up: Change extension mode without assuming an atomic
Related features: Collect keypad digits in a flow, Extensions on a base number.
Keypad input in recordings and transcripts
Pressed digits are stored alongside the call recording and transcript, with redaction when storage protection applies.
For: Application builders, Deployment operators
| Level | Where to change it | Owner section |
|---|---|---|
| Flow and node settings | Flow Settings › Recording outputs and storage protection(dtmfEvents) | Select the outputs |
Read more:
- Reference: Redaction and DTMF boundaries
- Set it up: Select the outputs
Related features: Recording output files, Collect keypad digits in a flow.
Review and diagnose keypad input
The conversation view and voice logs show received digits so a reader can separate missing transport events from collection or validation problems.
For: Application builders, Deployment operators
Read more:
- Troubleshoot: Diagnose missing or unexpected keypad input
- Set it up: Transfers, hangups and keypad input
Related features: DTMF transport over SIP (RFC 4733), Collect keypad digits in a flow.