Our agent is not joining the calls . Seems to be an issue with SIP. What it could be ?

Thanks for reaching out, Waleed. I'm an AI assistant and I'm here to help. Give me a moment while I research this topic.

1. Example failed calls (last 3): TimeRoomTrunkFromToStatus204909`call-e679f4f2ST_Fdf8RSMim3D3`+19135380173+15125538217SIP participant never joins room205405`call-9cc519bfST_Fdf8RSMim3D3`+19135380173+19135380173Same205619`call-3bfcca8cST_Fdf8RSMim3D3`+19135380173+19373965194Same Agent dispatches succeed (

AD_dcCXa3KtvPzE

,

AD_cnsuugZXvrk4

,

AD_wrviXGUoHJvH

) but the SIP participant never appears in the room. No

sip.callStatus=active

, no

track_subscribed

. Errors:

TwirpError(code=not_found, message=requested room does not exist, status=404)

— agent polls for participants but room seems to not exist from API perspective. 2. SIP trunk config: • Trunk 1:

ST_Fdf8RSMim3D3

— from +19135380173 Trunk 2:

ST_NucAgqbKTVxB

— from +19138286060 Provider: Twilio (credential name: "Prod Twilio") • LiveKit Cloud URL:

<wss://sdr-evolv-3iql8wce.livekit.cloud>

• Region: US East B 3. Dispatch config: • Explicit agent name:

Drew-38b

• Single agent worker (1 replica) • Process count: ~40 PIDs •

num_idle_processes=2

configured 4. What was working: • Campaign calls were connecting fine until ~20:10 UTC (31 answered calls in 60min window) • After ~20:15 UTC, zero calls connect — to any number, on either trunk 5. Key error:

TwirpError(code=not_found, message=requested room does not exist, status=404)

This fires when the agent tries to list participants in the room it was dispatched to. This looks like a LiveKit Cloud SIP routing issue. The rooms are created, agents dispatched, SIP participants created — but the SIP media stream never connects to the room.

Thanks — this is very helpful detail. I’ll focus on the SIP participant not appearing and the

room does not exist

Twirp 404 when the agent polls participants. Quick summary of what I’m addressing: the SIP trunks and dispatch are reaching LiveKit (agent dispatches succeed) but the SIP participant/media never connects to the room and the room appears missing from the API. Immediate checks I want you to confirm or share (these will narrow root cause quickly): 1. Room lifecycle • When the SIP INVITE arrives, is the room being created by your app or by LiveKit SIP routing? Do you have logs showing a room creation event at call start (room name =

call-…

)? • Does your app or an automation ever immediately delete rooms on empty state or on participant disconnect? If yes, could a race delete the room before the agent polls? 1. SIP-to-LiveKit mapping • Confirm the room name that the trunk is set to route to exactly matches the room the agent expects (case-sensitive). You listed room IDs like

call-e679f4f2

— is that the literal SIP To/room_prefix used in the trunk dispatch? • If you use

room_prefix

, confirm the prefix and resulting full room name match. 1. LiveKit Cloud region / URL consistency • You’re using

wss://sdr-evolv-3iql8wce.livekit.cloud

(US East B). Are both trunks and your agent workers configured to use the same LiveKit Cloud region/URL? A mismatch can make the SIP leg land in a different LiveKit instance where the agent’s room doesn’t exist. 1. SIP provider behavior change at ~20:15 UTC • Twilio is the provider. Did anything change on Twilio (credential rotation, IP address changes, webhook updates, trunk settings) around 20:15? Can you confirm Twilio is still successfully sending the INVITE to LiveKit (Twilio call logs/webhook delivery show 200 to LiveKit)? 1. Trunk auth / allowed IPs • Confirm LiveKit’s SIP ingress is still allowing Twilio’s IPs and the trunk auth credential used by Twilio is unchanged. An auth/IP block would prevent SIP from creating the participant/room. 1. Agent worker capacity & timing • You have a single agent worker with ~40 PIDs and

num_idle_processes=2

. For testing, can you bring up a second agent replica (even temporarily)? Single-replica limits can cause missed connections under load or during restart windows. 1. LiveKit logs and Twirp calls • Please share an anonymized excerpt of LiveKit Cloud logs (or agent logs) around one failed call showing: ◦ SIP INVITE receipt (or Twilio webhook/call log) timestamp ◦ Any LiveKit SIP handler log for that INVITE (showing room creation or failure) ◦ The Twirp 404 log you quoted with timestamps This will confirm whether the SIP INVITE reached LiveKit and whether room creation succeeded. Next steps I can take after you share the items above: • If the SIP INVITE reached LiveKit but no room was created: check routing/room_prefix and region mismatch, and I’ll show specific log fields to confirm where the INVITE landed. • If INVITE did not reach LiveKit: we’ll focus on Twilio trunk auth/IP/webhook delivery and Twilio debug logs. • If room is created but immediately deleted: I’ll suggest checks for empty-room TTLs and any automation deleting rooms. If you prefer, send one complete call trace (Twilio SID, timestamps, anonymized LiveKit logs) for one failed call and I’ll pinpoint which hop is failing. , with interactive elements

Here's the complete info to share with LiveKit support: Full Call Trace for Failed Call

3bfcca8c

Call to +19373965194 (lumber company) via trunk ST_Fdf8RSMim3D3 from +19135380173 Timeline:

20:56:19.000 - Room created: call-3bfcca8c-b468-4c70-9e5a-4e313bb70d16 (sid=RM_sfam6EkQtDc3)
20:56:19.000 - Agent dispatched: AD_wrviXGUoHJvH, agent_name=Drew-38b
20:56:19.000 - SIP participant created: SCL_9SLJQNxCv73v
20:56:20.000 - Agent process starts, joins room
20:56:24.159 - Agent reports call_ringing
20:56:24+    - Agent polls participants: API=1 (only agent, no SIP callee)
             - Repeated polling every 3s, never finds SIP callee
             - TwirpError(code=not_found, message=requested room does not exist)

Answers to LiveKit support questions: 1. Room lifecycle: Room created by OUR APP via

api.CreateRoomRequest

with

empty_timeout=300

(5 min) Room name =

call-{uuid}

(e.g.

call-3bfcca8c-b468-4c70-9e5a-4e313bb70d16

) We do NOT delete rooms on empty state — only on ring timeout (45s) or max duration (5min) • The

empty_timeout=300

is set on creation. The

TwirpError(not_found)

happens within seconds — too fast for empty timeout 2. SIP-to-LiveKit mapping: Room name is created by our app, NOT by SIP routing Our app creates room → dispatches agent → creates SIP participant in the SAME room No

room_prefix

used — explicit room name in

CreateSipParticipantRequest

• SIP participant SID confirms creation:

SCL_9SLJQNxCv73v

3. Region/URL: Agent worker:

<wss://sdr-evolv-3iql8wce.livekit.cloud>

(US East B) Both trunks configured on same LiveKit Cloud project • Agent registered as:

agent_name=Drew-38b

,

id=AW_nLUZRfZKPonT

, region

US East B

4. What changed at ~20:15 UTC: • Nothing changed on our side — no deploys, no config changes • Twilio credentials unchanged • Campaign calls to OTHER numbers were working at 2005 2010, then all calls stopped connecting 5. Trunk auth: • No changes to trunk credentials or allowed IPs • SIP participant creation SUCCEEDS (returns SCL_xxx) — so LiveKit API accepts the request • But the SIP media never connects to the room 6. Agent capacity: • Single agent worker,

num_idle_processes=2

• Not resource constrained: CPU 3.73%, Memory 1.1GB/7.6GB at time of failure • Agent process initializes and joins room successfully 7. Key observation:

CreateSipParticipantRequest

returns SUCCESS (SCL_xxx) Agent dispatches to room and joins • But when agent calls

list_participants

on the room, gets

TwirpError(not_found, requested room does not exist)

• The room was just created seconds ago and the agent is IN it, yet the API says it doesn't exist This suggests a LiveKit Cloud internal routing issue where the room exists on one node but the API/SIP queries hit a different node.

I don't have the answer you're looking for. You could also try asking your question: • in one of the other Slack channels or • to https://deepwiki.com/livekit/livekit_composite which is trained on all LiveKit source code If you find the answer, please post it here to help others!