> ## 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.

# Other and custom SIP providers

> Safe setup rules for PBXs and providers without a verified global signaling allowlist

A saved hostname proves only that an endpoint was entered. It does not prove direction, authentication, source addresses, or a successful inbound call. Keep the exact DID, route it to the platform SIP FQDN, and obtain current provider-to-destination authentication details. If no stable list is published, ask support for the account's complete **SIP-signaling source CIDRs** and failover regions. Never use media ranges or another customer's addresses.

## 1&1

**Status:** `sip.1und1.de` is normally a registrar/termination host, not evidence of external FQDN forwarding. No verified global source list is included. **Action:** confirm product support, sent DID format, and all signaling sources with 1&1.

## Plusnet / Fonial

**Status:** Fonial documents SIP users and trunking, but SIP-URI forwarding is account-dependent. `sip.plusnet.de` is an outbound host, not an inbound allowlist. **Action:** configure outbound separately and obtain current forwarding/source details from Fonial.

## 3CX

**Status:** a customer-specific FQDN identifies a PBX, not its upstream carrier; sources depend on hosting and NAT. **Action:** use a supported generic IP trunk, disable registration for FQDN delivery, and allow only verified public PBX/SBC signaling IPs.

## Localphone

**Status:** a `localphone.com` endpoint alone is not a verified inbound profile. **Action:** confirm external SIP-URI routing, DID format, transport, and signaling sources with Localphone.

## i-pbx

**Status:** the hostname can identify a PBX or reseller; no global list is verified. **Action:** identify the actual operator and obtain account-specific public signaling addresses.

## DIDWW

**Status:** routing a DID to a SIP URI is supported, but auth and sources follow current account/trunk documentation. **Action:** use current DIDWW sources; never reuse DIDLogic addresses.

## Zadarma

**Status:** credentials and routing are account-specific; no global list is verified here. **Action:** confirm FQDN forwarding plus documented downstream Digest or current signaling CIDRs.

## sipcall

**Status:** capabilities vary by product and region. **Action:** ask support for external SIP-URI routing, number format, transport, and current sources.

## Starface

**Status:** this is a PBX; its public address depends on deployment, SBC, and NAT. **Action:** route to the platform FQDN and allow only verified static public PBX/SBC addresses.

## Asterisk / FreePBX

**Status:** self-managed PBX; no vendor-global list exists. **Action:** use its static public signaling IP/CIDR, exact DID rewrite, matching TCP/TLS, and separate RTP rules.

## RingCentral

**Status:** generic SIP/BYOC depends on the purchased product. **Action:** confirm external SIP destination support and request current regional signaling ranges.

## Genesys Cloud

**Status:** BYOC Cloud uses account/region-specific trunks and edge endpoints. **Action:** follow the current Genesys BYOC design and only its supplied addresses.

## Five9

**Status:** SIP interconnection is an implementation-managed enterprise integration. **Action:** obtain destination, transport, codecs, auth, and source networks from the Five9 team.

## Amazon Chime SDK Voice Connector

**Status:** Voice Connectors use region-specific signaling information. **Action:** use the current data for the selected AWS region; never reuse another region's addresses.

## Aircall

**Status:** external SIP forwarding/BYOC depends on product and enablement. **Action:** confirm FQDN delivery and obtain current account sources from Aircall.

## Placetel

**Status:** no verified direct external-FQDN profile is documented here. **Action:** treat it as unsupported until Placetel confirms route, number format, auth, transport, and source ranges in writing.

## Peoplefone

**Status:** capabilities and SBC addresses vary by country/product. **Action:** request the exact external SIP route and regional source networks for the account.

## NFON

**Status:** Cloud PBX interconnect is product-controlled; no global list is asserted. **Action:** use a support-assisted setup and only the destination/source networks supplied by NFON.

## Sipgate

**Status:** trunking and forwarding are product-specific; no global list is asserted. **Action:** confirm external SIP-URI routing and current signaling sources before saving.

## Voxbi / Mixvoip

**Status:** these public host classes appeared in legacy saved trunks, but no current first-party provider-to-platform authentication profile was verified. **Action:** identify the exact product and region, then obtain the current FQDN-routing method and complete signaling sources from the provider or account portal.

## TeamFON / TeamsIP

**Status:** these hosted-telephony host classes appeared in legacy saved trunks; a saved hostname or credential mode is not proof of downstream Digest support. **Action:** confirm the account's external SIP destination support, DID format, transport, and current public signaling sources.

## Required confirmation

Ask whether the DID can be delivered to an external FQDN without REGISTER; the exact DID format in the Request-URI; whether the provider authenticates toward the destination with Digest and where those origination credentials are set; otherwise all signaling CIDRs and failover regions; TCP 5060 or TLS 5061; and whether SRTP is required.

Only an external call with a platform inbound record, the assigned assistant, and two-way audio confirms the integration.

Reject allowlist entries that contain prose, placeholders, hostnames, or unrelated public resolvers such as `8.8.8.8`. A provider network written without its CIDR prefix is only one host and must not be silently expanded or corrected.

Sources: [LiveKit](https://docs.livekit.io/telephony/accepting-calls/inbound-trunk/), [DIDWW](https://doc.didww.com/), [Fonial](https://www.fonial.de/hilfe/trunking/einrichtung-trunking), [3CX](https://www.3cx.com/docs/manual/sip-trunks/), [Asterisk](https://docs.asterisk.org/), [Genesys BYOC](https://help.mypurecloud.com/articles/about-byoc-cloud/), [Amazon Chime](https://docs.aws.amazon.com/chime-sdk/latest/ag/voice-connectors.html), [Zadarma](https://zadarma.com/en/support/), [sipcall](https://www.sipcall.ch), [Starface](https://knowledge.starface.de/), [RingCentral](https://developers.ringcentral.com/), [Five9](https://documentation.five9.com/), [Aircall](https://support.aircall.io/), [Placetel](https://www.placetel.de/hilfe), [Peoplefone](https://www.peoplefone.com/), [NFON](https://support.nfon.com/), [Sipgate](https://help.sipgate.de/). Accessed 22 August 2026.