Hi, SIP inbound returns 503 but no record in Calls dashboard Project: alertivo (id: p_23wunvd1nk2), region Germany 2. Inbound SIP calls from Twilio Elastic SIP Trunk fail with SIP 503, but nothing appears in the Calls dashboard (Telephony → Calls, past 24h shows “No results”). I’m at my wit’s end on diagnosis. Setup: - Twilio origination URL: sip:23wunvd1nk2.sip.livekit.cloud;transport=tcp - Inbound trunk ST_tjNxEUu9gGtf, numbers +420910923523,420910923523, no auth, encryption DISABLE - Dispatch rule SDR_g3rVynwCybMM, Individual (Caller), roomPrefix: “call-“, references the trunk, room_config.agents: [{agent_name: “alertivo-support”}] - Agent worker registered as agent_name: “alertivo-support” (livekit-agents 1.5.4, AgentServer + @breezy-insurance-66772.rtc_session(agent_name=...) pattern) - Twilio call SID example: CA097cd1e8a4f4a2f391f7534c7a033f62, returns: 503 service error with sip:+420910923523@23wunvd1nk2.sip.livekit.cloud;transport=tcp What works: - Manual dispatch via lk dispatch create --agent-name alertivo-support --room ... works end-to-end — agent receives job, connects Deepgram STT, etc. - SIP OPTIONS over TCP to 23wunvd1nk2.sip.livekit.cloud:5060 returns SIP/2.0 200 OK - SIP URI on Trunks page shows sip:23wunvd1nk2.sip.livekit.cloud (no custom port) - UDP 5060 times out — confirming TCP-only behavior What doesn’t: - TCP INVITE returns 503 every time (5x retries visible in Twilio debugger) - Calls dashboard shows nothing for these attempts — so the INVITE never becomes a registered “call” in LiveKit Any idea why the SIP edge returns 503 without registering the call? Is there a known issue with room_config.agents auto-dispatch for SIP inbound, or a specific flag I’m missing?

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Check trunk number formatting and dispatch rule

The solution was provided here https://community.livekit.io/t/sip-inbound-returns-503-but-no-record-in-calls-dashboard/930/2?u=cwilson Don't add the number without the

+

in the turnk

Thank you very much for your support.