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

# Sinch Elastic SIP Trunking

> Configure Sinch static endpoint routing and signaling CIDRs

## Recommended profile

Create a Sinch static endpoint that targets the platform SIP FQDN and assign the DID. The official LiveKit quickstart uses TCP 5060; secure trunking uses TLS 5061.

In the platform, use the exact `+E.164` DID and **Provider source IPs**. Sinch ACL/digest choices documented for calls into Sinch belong to outbound authentication, not the Sinch-to-platform inbound path.

Allow all eight Sinch SIP-signaling CIDRs:

```text theme={null}
206.146.131.0/28
206.146.133.0/28
206.146.134.0/28
206.146.136.0/28
206.146.137.0/28
206.146.138.0/28
206.146.139.0/28
206.146.141.0/28
```

Do not add the separate RTP/media ranges as inbound authentication addresses.

## Validate

Call the assigned DID externally and confirm a new inbound record, the expected assistant, and two-way audio. If signaling arrives but audio fails, investigate media separately instead of widening the signaling allowlist.

Sources: [LiveKit Sinch guide](https://docs.livekit.io/telephony/start/providers/sinch/), [Sinch Elastic SIP Trunking networks](https://community.sinch.com/t5/Elastic-SIP-Trunking/Getting-started-with-Elastic-SIP-Trunking/ta-p/11380). Accessed 22 August 2026.