Inbound SIP Calls With OPUS Codec Only Blocked

What to do

• Check whether you use Twilio SIP Interface US1. Check your stack

  Paste a package.json, lockfile, Terraform or a list of domains at down.guide/stack to see every provider you depend on.

• Confirm your retries, queues and scheduled jobs caught up after the 2h 51m it lasted.

  Anything that failed between 2026-09-15 20:09 UTC and 2026-09-15 23:00 UTC may need a replay.

• Subscribe to Twilio's feed to hear about the next one first. RSS feed

  https://down.guide/feed?provider=twilio works in Slack (/feed subscribe), Discord feed bots and any RSS reader.

Updates from Twilio 3

1. monitoringSep 15, 2026, 8:09 PM UTC

   We have identified an issue with some calls made to Twilio using Programmable Voice SIP interfaces and OPUS codec may unexpectedly be rejected. Customers would see a SIP 488 responses for those requests. Our engineering team is working on a fix. We will provide another update in 2 hours or as soon as more information becomes available.

   provider

2. monitoringSep 15, 2026, 9:54 PM UTC

   Our engineers have implemented a fix and are monitoring system performance. We will provide another update in 2 hours or as soon as more information becomes available.

   provider

3. resolvedSep 15, 2026, 11:00 PM UTC

   Our engineers have monitored the fix and confirmed the issue with Twilio Programmable Voice SIP interfaces and OPUS code has been resolved. All services are now operating normally at this time.

   provider

Corrections

None so far.

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