> ## 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.

# Twilio Elastic SIP Trunking

> Configure Twilio origination to the platform and allow Twilio signaling CIDRs

## Recommended profile

1. In Twilio Elastic SIP Trunking, add an Origination SIP URI in the form `sip:<platform-sip-fqdn>;transport=tcp` and assign the DID to the trunk.
2. In the platform, enter the exact `+E.164` DID and select **[Provider source IPs](/telephony/sip-trunks#inbound-receiving-calls)**.
3. Do **not** use platform inbound digest. Twilio credential lists authenticate customer-to-Twilio termination, not Twilio-to-platform origination.

Allow every Twilio regional signaling CIDR for failover:

```text theme={null}
54.172.60.0/30
54.244.51.0/30
54.171.127.192/30
35.156.191.128/30
54.65.63.192/30
54.169.127.128/30
54.252.254.64/30
177.71.206.192/30
```

Twilio documents UDP/TCP signaling on port 5060 and TLS on 5061. The list above is for signaling; do not substitute Twilio media ranges.

For outbound calls, configure the Twilio termination domain and a Twilio credential list separately. A Twilio termination host normally follows `<name>.pstn.twilio.com`; do not paste an Origination SIP URI into that field.

<Frame caption="Two call directions — conceptual diagram">
  ```mermaid theme={null}
  flowchart LR
    A["Caller"]
    B["Twilio trunk"]
    C["Famulor assistant"]
    D["Destination number"]
    A --> B
    B -->|Origination| C
    C -->|Termination| B
    B --> D
  ```
</Frame>

These examples show the relevant settings; the layout can differ in your provider’s current console.

<Frame caption="Configuration example — Twilio's Termination page — where the outbound SIP URI and IP ACLs live">
  <img src="https://mintcdn.com/ouraicall/LGhF4w_dCForynTL/resources/twillio-setup-termination1.jpeg?fit=max&auto=format&n=LGhF4w_dCForynTL&q=85&s=cb7c26b07f1fa31ae1e43d6aa2ffb7c4" alt="Twilio Elastic SIP Trunking Termination page with the Termination SIP URI field and IP Access Control Lists" width="859" height="868" data-path="resources/twillio-setup-termination1.jpeg" />
</Frame>

## Troubleshooting

**Outbound calls don't connect, but inbound works** — check the Termination SIP URI first for a stray space or a copy-paste error; it must be exact (`<name>.pstn.twilio.com`), with no extra whitespace. Twilio also publishes localized termination URIs — use the one closest to your own region rather than the default global host before you start changing credentials.

**International calls fail or are rejected** — open **Voice → Settings → Geo permissions** in Twilio Console and allow the destination countries and number ranges you need. These permissions apply to both Programmable Voice and Elastic SIP Trunking. [Twilio’s current instructions](https://www.twilio.com/docs/sip-trunking/voice-dialing-geographic-permissions).

## Validate

Call the Twilio DID externally. Confirm a new inbound record, correct assistant routing, and two-way audio. A Twilio call log without a corresponding platform inbound call is not proof of delivery.

Sources: [Twilio signaling IPs](https://www.twilio.com/docs/sip-trunking/ip-addresses), [Twilio Elastic SIP Trunking](https://www.twilio.com/docs/sip-trunking). Accessed 22 August 2026.


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