Thanks — I’m responding to your question about whether LiveKit outbound SIP trunks need special configuration to dial phone number extensions (DTMF) when Twilio works. Short answer: No trunk config is required. LiveKit supports DTMF for outbound calls (RFC 2833 / SIP INFO) and the recommended pattern is: 1. Place the outbound call to the main number using

CreateSIPParticipant

. 2. After the call is answered (IVR/auto-attendant greeting), send the extension digits using the

send_dtmf_events

tool (it sends digits sequentially with a short delay and supports 0–9, *, #, A–D). If extensions are failing for some users, check these points: • Ensure your logic waits until the call is answered before sending DTMF (IVR prompts often must finish first). • Verify you’re using

send_dtmf_events

(or equivalent) to emit DTMF after connect. • Confirm the extension digits being sent are correct and formatted as the destination expects. • If you rely on in-channel timing (pauses), try inserting a short delay before sending digits. If you’d like, tell me: • How you currently initiate the outbound call (API call/sample code), • Whether you’re sending DTMF and when (immediately on dial vs. after answer), and I’ll suggest exact code/flow adjustments. Sources: Agents telephony integration | LiveKit Documentation | examples/dtmf | livekit/livekit_composite | DeepWiki | send_dtmf_events | LiveKit Documentation | Prebuilt tools | LiveKit Documentation | Making calls overview | LiveKit Documentation, with interactive elements