404 "No trunk found" — Zadarma (Bulgaria) to LiveKit Cloud — GeoDNS routing issue?

Hi,

We’re getting 404 No trunk found on every inbound SIP call from Zadarma (Bulgarian SIP provider) to our LiveKit Cloud project. After extensive debugging we believe this is a GeoDNS/anycast routing issue similar to the one described here: SIP 404 “No trunk found” — DNS routing mismatch on LiveKit Cloud

Environment:

  • LiveKit Cloud project SIP URI: ytlj4qounpm.sip.livekit.cloud

  • SIP provider: Zadarma (zadarma.com) — Bulgarian virtual number

  • Inbound trunk ID: ST_o3tpcif66zzu

  • Dispatch rule configured with agentName matching a running Python agent :white_check_mark:

What the SIP log from Zadarma shows:

To: <sip:35924373387@ytlj4qounpm.sip.livekit.cloud>
SIP/2.0 404 No trunk found
Via: SIP/2.0/UDP 185.45.152.192:5060
src: 185.45.152.200 (Zadarma PBX)
dst: 161.115.161.184:5060

What we confirmed:

  • TCP port 5060 open and responding :white_check_mark:

  • nslookup ytlj4qounpm.sip.livekit.cloud161.115.161.26 and 161.115.161.184 :white_check_mark:

  • Zadarma IP ranges correctly added to allowedAddresses :white_check_mark:

  • LiveKit → Telephony → Calls shows 0 calls — never registers anything

  • Call forwarding to a real phone number works perfectly :white_check_mark:

  • Python agent running and registered as bulgarian-agent :white_check_mark:

Trunk configurations tested (all return 404):

  • With numbers: ["+35924373387", "35924373387"]

  • With numbers: [] (empty — accept any number)

  • With and without allowedAddresses

  • With and without authUsername/authPassword

Suspected cause: Zadarma sends from Bulgaria and likely hits a different LiveKit SIP server than the one where our trunk is registered — same pattern as the DNS routing mismatch thread above.

Question:

  1. Is ytlj4qounpm.eu.sip.livekit.cloud a valid EU region-pinned endpoint we can use?

  2. Will region pinning solve the GeoDNS mismatch?

  3. Is there anything else in the trunk configuration we might be missing?

Thanks!

This is almost always either wrong phone number or sometimes you have the number defined twice maybe even twice in the same trunk.

I took a look at the server logs and I see the issue. The problem is you are using the WebRTC URI instead of the SIP URI. Look here and use the SIP URL for the SIP invites: