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The legacy SIP endpoint is being removed

Removal date: 09/30/2026
Migrate from sip:5t4n6j0wnrl.sip.livekit.cloud to sip:sip.retellai.com.
The legacy SIP endpoint sip:5t4n6j0wnrl.sip.livekit.cloud has been deprecated since November 2025 and will be retired on 09/30/2026. Route your inbound calls to the supported Retell SIP server sip:sip.retellai.com instead. See the Connect to custom telephony guide for setup. After 09/30/2026, calls sent to sip:5t4n6j0wnrl.sip.livekit.cloud may no longer connect.

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Who is affected

Only integrations that dial or route directly to the hardcoded 5t4n6j0wnrl.sip.livekit.cloud host. If your trunk or code already targets sip.retellai.com, no change is needed.

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Migration

  • Elastic SIP trunking: update the SIP server URI/Origination URI on your trunk from sip:5t4n6j0wnrl.sip.livekit.cloud to sip:sip.retellai.com. If you pin a transport, keep it on the new host: sip:sip.retellai.com;transport=tls (also ;transport=tcp or ;transport=udp).
  • Dial to SIP URI: dial each call to sip:{call_id}@sip.retellai.com, replacing {call_id} with the call_id returned by Register Phone Call — previously sip:{call_id}@5t4n6j0wnrl.sip.livekit.cloud.
  • Allowlist Retell’s IP ranges: make sure your firewall permits Retell’s SIP CIDR blocks, listed in the custom telephony guide. Many providers require this before they accept traffic to the new host.
  • TLS / mTLS: sip.retellai.com presents Retell’s server certificate; if you pin a root CA or use mTLS, follow the Security center section.
No other part of your Retell configuration changes — only the SIP hostname you route to.