> ## Documentation Index
> Fetch the complete documentation index at: https://docs.retellai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Legacy SIP endpoint removed (09/30/2026)

> Retell retires SIP endpoint sip:5t4n6j0wnrl.sip.livekit.cloud on 09/30/2026; migrate elastic trunks and dial-to-sip integrations to sip:sip.retellai.com.

## The legacy SIP endpoint is being removed

**Removal date:** 09/30/2026

<Note>
  Migrate from `sip:5t4n6j0wnrl.sip.livekit.cloud` to `sip:sip.retellai.com`.
</Note>

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](/deploy/custom-telephony) guide for setup.

After 09/30/2026, calls sent to `sip:5t4n6j0wnrl.sip.livekit.cloud` may no longer connect.

## 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.

## 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](/api-references/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](/deploy/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](/deploy/custom-telephony#security-center) section.

No other part of your Retell configuration changes — only the SIP hostname you route to.