BYO SIP trunk

Already have numbers and a SIP provider (Telekom, sipgate, Twilio, Telnyx, Plivo, or any standards-compliant trunk)? Connect them directly — calls flow between your provider and the platform’s voice infrastructure without porting anything.

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Setup checklist

1. Copy the platform SIP URI from Settings → Phone numbers → Add SIP integration (or Carrier import). Pick a SIP region (default: global) so inbound signaling terminates where you need it (e.g. EU).
2. At your provider, set that URI as the origination / forwarding destination for your numbers.
3. Create the trunk in the platform (form below) — inbound auth + outbound termination.
4. Assign numbers to assistants and test inbound, then one outbound test call.

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Trunk type

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Inbound (receiving calls)

• Your phone number (DID) — public E.164 customers dial; must match what the carrier forwards to the platform SIP URI.
• Inbound authentication
  • SIP username/password (recommended) — digest auth.
  • Provider source IPs — only if the carrier cannot do digest and publishes stable SIP source IPs/CIDRs. Do not use overly wide ranges.
• At the provider: forward / originate to the platform SIP URI you copied.

Incoming calls are matched to the assistant you assign, exactly like marketplace numbers.

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Outbound (calling out)

• Termination address — provider SIP host only (e.g. sip.telnyx.com). No sip: prefix, no port.
• Transport — AUTO (recommended), UDP, TCP, or TLS. Secure trunking always uses TLS.
• Outbound region — where the platform originates the call. Prefer Automatic, or the country closest to your customers / carrier POP.
• Outbound calling number format — how the FROM number is sent to the carrier. Must match the carrier’s setting (e.g. Telnyx Origination Number Format):
  • International with + (recommended for most)
  • International without +
  • National (no country code)
• Credentials
  • Shared (recommended) — one username/password for inbound and outbound.
  • Separate — distinct inbound vs outbound secrets when the carrier requires it.
• Outbound authentication — username/password (recommended). The platform has no static outbound IPs, so carrier IP allowlists usually fail. Use “no credentials” only if the carrier explicitly allows unauthenticated outbound.

Outbound calls and campaigns can then use your trunk and your caller IDs.

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Advanced

Expand Advanced when creating or editing a BYO trunk: HD Voice (G.722): enable on the Telnyx connection/codec settings when needed (supported with Telnyx, not Twilio).

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Edit later

Existing trunks are edited from Numbers → Configure → Carrier Settings (not from a separate trunk list on Add SIP integration).

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EU routing

For EU customers, SIP traffic can terminate on the platform’s EU-pinned SIP endpoint, keeping media and signaling inside the EU — relevant for GDPR documentation. Media/agent processing runs in Frankfurt (eu-central).

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Limits and behavior

• E.164 numbers on BYO trunks count against the same plan limit as purchased numbers (max_own_numbers).
• Calls over your own trunk avoid the platform’s per-destination carrier surcharge — your provider bills termination directly. Plan minutes are still consumed; see billing.
• All assistant features — flows, warm transfer, recording, monitoring — work identically on BYO trunks.

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API

Create and manage trunks via the Public API (POST /sip-trunks and related endpoints in the API reference). The same fields as the UI (trunk_kind, calling_number_format, transport, Advanced maps, etc.) are accepted on create; passwords are never returned.