# LiveKit: Degraded SIP Performance in US West

- Provider: [LiveKit](https://outages.cc/livekit.md)
- Type: Incident
- State: Resolved
- Worst impact: Degraded performance
- Started: 2026-10-16 16:04 UTC
- Resolved: 2026-10-16 17:30 UTC (lasted 1 h 26 min)
- Components: US West - SIP
- Official update: https://stspg.io/dwszh1v29gsq

## Updates from LiveKit

### postmortem, 2026-10-22 14:22 UTC

**Root Cause** On 2026-10-16, a subset of SIP calls in our US West region failed. Two of our SIP servers advertised IPv6 addresses for signaling and media, which many carrier providers don't support. Carriers rejected outbound calls routed through these servers, and inbound calls were answered but dropped almost immediately without audio. We had recently started running SIP in a US West cluster that uses both IPv4 and IPv6 networking and our SIP servers didn't enforce IPv4 addresses. **Technical Details** When a SIP server starts, it determines its public address by querying an external address-lookup service. On the two affected servers, our primary lookup service didn't respond in time so they fell back to a backup service that returned their IPv6 address instead. Nothing in the SIP server checked that the address it advertised was IPv4. **Timeline \(UTC\)** 2026-10-16 14:49 - First affected SIP server started with an IPv6 address; call failures began 2026-10-16 15:41 - Second affect

### resolved, 2026-10-16 17:30 UTC

This incident has been resolved. Between 14:49 UTC and 15:58 UTC, approximately 14% of outbound calls and 5% of inbound calls in US West failed. We will follow up with more details surrounding the root cause and preventative actions in a postmortem.

### monitoring, 2026-10-16 16:57 UTC

We estimate that approximately 14% of outbound calls and 5% of inbound calls in US West failed between 14:49 UTC and 15:58 UTC. We will follow up as soon as possible with more details.

### monitoring, 2026-10-16 16:35 UTC

We applied mitigation as of 15:58 UTC and SIP outbound connection success has returned to normal. We are continuing to monitor before marking this resolved.

### identified, 2026-10-16 16:12 UTC

We have identified the source of the issue and are working to route around the impact.

### investigating, 2026-10-16 16:04 UTC

We are investigating degraded SIP performance in US West starting at 14:49 UTC affecting new outbound calls.