> ## Documentation Index
> Fetch the complete documentation index at: https://docs.famulor.io/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. Sinch's static-endpoint field expects the port and transport appended to the hostname, not a bare FQDN — use `<platform-sip-fqdn>:5060;transport=tcp` for standard signaling, or `:5061;transport=tls` for secure trunking.

In the platform, use the exact `+E.164` DID and **[Provider source IPs](/telephony/sip-trunks#inbound-receiving-calls)**. 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.

Source: [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.