SIP trunking
Keep your phone system. Connect it to more.
Connect your PBX, softphone or SIP application to Bird. Keep your call-handling logic, with inbound and outbound calling, caller identity and call records in one workspace.
The path of a call
ExampleYour phone system
PBX, softphone or SIP application
Bird SIP trunk
Authenticate identity and destination
Customer’s phone
Connect signaling and two-way audio
One place to investigate
Follow both directions in call records and events.
Illustrative connection paths. Configure and test both call directions.
Trusted every day by teams that build world-class software
Read more customer storiesThe connection
How does SIP trunking work?
Your phone system sends a call request to its Bird trunk address. Bird authenticates the request, checks whether the call is allowed and connects the carrier leg. SIP establishes the session; media carries the conversation. Both paths need to work for a successful call.
Keep your application
Use a PBX, a desktop softphone or a SIP-capable application. Read the connection details from the trunk, then match transport, authentication and media settings in your client.
Separate the directions
Outbound calling lets your equipment place calls through Bird. Inbound calling delivers calls from your numbers to the gateways you configure. Turn on and test each direction deliberately.
Control the entry point
Choose who can place calls.
Give each site or application the trunk configuration it needs. Use IP allow lists for known equipment, allowed keys for authenticated clients, or short-lived session credentials for browser and temporary clients. A trunk address on its own grants no calling permission.
- 01
Prepare your identity
Use an eligible Bird number or verify a number you control. The presented caller identity and the destination both participate in the admission checks.
- 02
Enable your markets
Turn on the destination countries you need and review current rates. A country being available is different from your workspace enabling it, and neither guarantees every number will connect.
Operate with evidence
From a failed ring to a useful answer.
Inspect the call’s status, final SIP response and any recorded rejection reason. A credential failure may happen before a call record exists; a destination or capacity refusal belongs to a different part of the path. Diagnose the stage before retrying.
Start with a real test
Place a call to a number your team controls. Check audio in both directions, keypad tones and clean hangup before routing customer traffic.
Keep capacity explicit
Plan concurrent calls and calling rate separately. Compare your workload with the applicable account limits and arrange capacity before a larger launch.
Questions about SIP trunking
Do I need to replace my PBX?
Can one trunk handle incoming and outgoing calls?
Can an AI voice application connect over SIP?
What happens if I disable inbound calling?
Does Bird Voice carry emergency calls?
Build the next part of your calling path
SIP trunking guide Follow the setup, requirements and operational checks.
Inbound routing Connect each number to your phone system, forwarding target or call sequence.
Browser calling Place an outbound call from your workspace with a browser phone and your SIP trunk.
Voice pricing Review published destination rates and relevant call components.
Related resources
Continue with the documentation, guides and examples for this topic. Resources are in English.
Talk to our Voice team
Connect your first trunk.
Prepare your trunk, caller identity and destinations. Test your PBX or softphone with a number your team controls before moving customer traffic.