Get straight answers on SIP trunks, AI voice agents, call routing, and billing.

Bird Voice connects your PBX, contact center, browser dialer, or AI voice agent to the global telephone network. You can place and receive calls over SIP trunks, automate IVR call sequences, record and transcribe conversations, and track call outcomes in real time.

Once your workspace has an active SIP trunk, a verified caller ID, and an enabled destination country, you can go online in the built-in browser phone and place a test call immediately, without configuring external SIP hardware.

You need three settings configured in your workspace: a SIP trunk that authorizes your equipment by IP address or API key, a verified caller ID to display on outbound calls, and the destination country enabled in your outbound allowlist. Bird provisions carrier routing for your workspace automatically.

Yes. Select a voice-capable phone number in your workspace and assign an inbound route. You can deliver incoming calls to a SIP trunk with an inbound gateway, run a published call sequence, ring a ring group of teammates in the browser phone, or forward them to a verified phone number. Newly acquired numbers reject incoming calls until you assign a route.

No. You can place calls directly from the browser phone in the dashboard, or connect an existing SIP softphone, IP PBX, or voice application using standard SIP signaling and media settings.

Yes. The Phone app in the Bird dashboard uses WebRTC so your team can answer ring-group calls and dial outbound calls from the browser, using your workspace's SIP trunk and verified caller IDs for outbound calls.

Calls are rated by destination country and numbering range. Each destination rate specifies a minimum billed duration followed by a rounding increment, so a rate with a one-minute minimum and six-second steps bills a ten-second answered call for one minute.

Billable talk time starts when the recipient answers and ends when either side hangs up. Unanswered calls do not incur talk-time charges, while phone number rentals and optional add-on services are billed according to the published rate card.

Voice usage is prepaid from your organization's wallet, which your monthly Voice plan deposit also funds. Bird checks your available wallet balance before placing each call, and refuses calls up front for insufficient balance when funds cannot cover the attempt.

Yes. Each workspace has a configurable daily voice spend cap in the Voice settings, up to your organization's maximum, which resets at midnight UTC. Once daily spend reaches that cap, additional calls are refused for exceeding the daily spend limit until the cap is raised or the next UTC day begins. Higher Voice plans increase the organization maximum, and you can request a custom ceiling from our team.

Open the call record in the dashboard call log to view the rated cost at full precision, excluding tax. To analyze spend across multiple calls, export your filtered call log as a CSV or review your workspace usage and invoices.

Voice traffic is governed by three independent caps: active calls in progress at the same time (concurrent calls), new call attempts started per second (calls per second), and total voice charges per UTC day (daily spend). Your Voice plan sets the concurrency, call-rate, and organization daily spend ceilings, while workspaces without a plan use pay-as-you-go defaults. Each workspace can also configure a lower daily spend cap within the organization ceiling.

Bird blocks the call during setup before dialing an upstream carrier. Your PBX receives a standard service-unavailable signaling response, while the call log records the exact limit that was reached (concurrent calls, calls per second, or daily spend) so you can adjust your pacing or capacity.

Yes. Upgrading your Voice plan under Billing and payments in the dashboard raises your concurrent-call, calls-per-second, and daily spend ceilings as soon as payment clears. If your call volume exceeds the highest self-serve plan, contact sales with your expected concurrency, call pacing, and destination mix.

Inspect the rejection reason on the call record in the dashboard. An outbound dialer that launches a burst of calls at once can exceed your calls-per-second rate limit even while total active calls remain well below your concurrency cap. Pace your dialer's call initiation rate before retrying.

No. Bird SIP trunks connect your existing IP PBX, SBC, or contact center platform to the telephone network using standard SIP transport, authentication, and audio codecs.

Yes. You can configure outbound and inbound traffic on the same SIP trunk. To receive incoming calls on that trunk, enable inbound calling, configure a delivery gateway, and assign a voice-capable Bird number to the trunk.

Yes. Any AI voice runtime that supports SIP signaling and RTP media can connect directly to a Bird SIP trunk. Your application manages speech recognition, model inference, and tool calls while Bird handles carrier connectivity.

Disabling inbound calling on a trunk resets any phone numbers routed to that trunk back to a rejecting route. If you re-enable inbound calling later, reassign those numbers to the trunk before resuming inbound traffic.

No. Bird Voice does not route emergency services calls, so maintain a local emergency-capable telephone connection for emergency dialing.

A SIP trunk connects your IP PBX, contact center, or voice application to the telephone network through Bird. Bird assigns your workspace a dedicated trunk domain, and you point your phone system at that domain to place and receive calls.

A single trunk handles traffic for most workspaces. You can create additional trunks when you want isolated IP allowlists, API keys, or Digest authentication settings for separate office locations, environments, or PBX clusters.

Configure your PBX with the trunk's SIP domain from the dashboard, the standard Bird SIP username, and the secret of an API key assigned to that trunk as the password. Point outbound signaling to the trunk domain on port 5060 for UDP or TCP, or port 5061 for encrypted TLS.

Yes. You can lock down a trunk using an IP allowlist, SIP Digest authentication with workspace API keys, or both together. Changes to allowed IP ranges and API keys take effect on the next call attempt.

The trunk domain stops accepting new call attempts immediately. Active calls already in progress finish normally, and historical call records from that trunk remain in your call log.

When your PBX starts a call, Bird replies with an authentication challenge, and your PBX resends the request with an authorization header signed using your Bird SIP username and API key secret. Your PBX transmits a cryptographic hash of the secret so the raw password stays off the network.

Bird supports SHA-256 and MD5. By default, Bird offers SHA-256 first and MD5 second, and your PBX selects the first algorithm it supports. If legacy equipment requires MD5 and fails when a challenge starts with SHA-256, configure the trunk to offer MD5 by itself.

Yes. When a trunk uses both methods, Bird checks the source IP address before issuing a password challenge, so traffic from an unlisted address is blocked before credential verification.

Add the new API key to the trunk first, update your PBX credentials, and then revoke the old key. Revoking or deleting a key immediately stops it from authenticating calls on the trunks where it was assigned.

A caller ID is a phone number your workspace is authorized to display on outbound calls. When you place a call, Bird checks the calling number against your workspace's eligible identities, including voice numbers managed in Bird and verified external numbers.

Add the number in international E.164 format in the dashboard and start the verification call. Answer the call, enter the spoken verification code in the dashboard, and confirm the number status shows verified before placing outbound calls.

If the verification attempts have expired, request a new code from the number's row in the dashboard to trigger a fresh call. If the number is still waiting for a code, remove the caller ID entry and add the number again.

Route the number temporarily to a phone or extension where someone can answer the verification call and capture the code. If the number cannot receive live voice calls, contact support to complete an ownership check.

New outbound calls presenting that number are refused immediately as an unverified caller ID. Active calls already in progress continue uninterrupted, and historical call logs for that number remain in your workspace.

Country allowlisting protects your balance from international toll fraud. Attackers who compromise a PBX typically dial high-cost international numbers, so keeping unused countries disabled caps your financial exposure to the regions where you actually do business.

Search for the country by name or two-letter ISO code on the Destinations page in the dashboard and switch its toggle on. Outbound calls to that country are permitted immediately.

The High risk badge marks destinations with elevated per-minute carrier rates or revenue-share numbering ranges that attract toll-fraud traffic. Keep high-risk destinations disabled unless you actively call customers there, and review the destination rate before enabling them.

Countries marked Available can be toggled on directly in the dashboard. If a country is marked Not supported, Bird cannot place calls there from your account; contact support so our team can review route availability and restore access where possible.

Enabling a country permits calls at the national level, but specific numbering ranges or regional prefixes within that country may still lack an active carrier route. Share the call ID with support so our team can inspect the dialed prefix and carrier coverage.

Provide both the destination number and the calling number in full international E.164 format, starting with a plus sign followed by the country code and subscriber number. The calling number must match a verified caller ID or eligible Bird number in your workspace, and no custom SIP headers are required.

STIR/SHAKEN cryptographically signs outbound caller identity so downstream carriers can verify the calling customer and phone number. Attestation reflects the verification level of the caller and number, though destination carriers still apply their own call-filtering and spam policies.

Open the call record in your dashboard call log. Your PBX receives a generic service-unavailable response over SIP, while the dashboard call record shows the specific rejection reason along with a direct link to the workspace setting that resolves it.

Fix the underlying rejection reason before retrying. For example, a call blocked for exceeding your calls-per-second rate limit will continue to fail until your dialer slows its pacing, and a call blocked for an unverified caller ID or disabled destination country requires a configuration update first.

No. It means the call connected. Join a confirmed business event, such as a booking or resolved case, to evaluate task success.

An active call has not completed rating. Read the final record after the call and rating lifecycle finish; a missing value is not a zero price.

Verify the signature, deduplicate using the webhook identity and tolerate out-of-order arrival. Reconcile the final result against the call record.

Review direction and the report’s filters explicitly. The mix of traffic and the applicable rated components may differ.

Join rated calls and their sessions to confirmed outcomes in your application. Include every relevant call leg and use a consistent period and definition of completion.

Completed calls show one of five statuses: Answered when the recipient picked up, No answer when the call rang out, Failed when carrier delivery did not complete, Rejected when Bird blocked the call before dialing or the recipient declined it, and Unknown when the final signaling state could not be determined.

Calls blocked by Bird appear as Rejected and include a rejection reason in the call log showing which account or trunk check failed. A Rejected status without a pre-dial block means the recipient declined the call. Carrier delivery issues appear as Failed along with the signaling response code.

Yes. The Live tab on the Calls page displays active calls across your trunks along with a live concurrency count. Each active call appears as Ringing while waiting for an answer or In progress once connected, and the view updates automatically.

Total duration measures the time from when Bird receives the call request until hangup, including ringing. Billable time measures the connected conversation from answer to hangup. Unanswered calls accumulate zero answered talk time. Check your rate card for applicable per-minute increments and service charges.

You can download a CSV from the Calls page that includes the full set of records matching your active filters across pages, fetch call logs programmatically through the Voice API using a read-scoped API key, or list call records from the Bird CLI.

Bird sends three call lifecycle webhooks: a call-initiated event when Bird accepts the call and begins routing, a call-answered event when the recipient picks up, and a call-ended event when the call finishes with its final status and duration. Unanswered calls skip the answered event and go straight from initiated to ended.

Calls admitted and then refused by a policy check emit a call-ended event with a rejected status, which you can reconcile against the call record. Calls turned away at the SIP edge before admission do not generate a call record or webhook events. Check the call log to confirm whether a call without a webhook completed or was blocked before admission.

Yes. Webhook deliveries can arrive out of sequence, so a call-answered notification may reach your endpoint after the call-ended notification. Compare the event timestamps in your handler so an older lifecycle transition does not overwrite a newer call state.

Deduplicate incoming deliveries using the unique webhook identifier header attached to each HTTP request. Network or signaling retries reuse the same webhook identifier for a given call lifecycle transition, allowing your handler to ignore duplicates safely.

Call costs and specific rejection reasons are stored on the call record in the call log. A rejected status on a call-ended event indicates either a pre-dial refusal by Bird or a call declined by the recipient. Inspect the call record to see the specific rejection reason and the final rated cost once billing completes.

Calls turned away at the SIP boundary before admission do not create a call record. Verify four settings on your trunk and PBX: the trunk has at least one allowed IP range or API key assigned, your traffic arrives from a public IP address on the trunk's allowlist, your SIP Digest credentials and hashing algorithm match the trunk configuration, and your PBX dials the trunk's exact SIP domain.

Open the call record in your dashboard call log, where the summary banner explains why the call was blocked and links directly to the setting that resolves it. Self-service rejection reasons cover an unauthorized source IP, an unverified caller ID, a disabled destination country, insufficient wallet balance, a reached daily spend cap, a reached concurrent-call limit, or a reached calls-per-second rate limit.

Some legacy SIP equipment fails to parse an authentication challenge that offers SHA-256 first. Configure the trunk's Digest authentication setting to offer MD5 by itself so your PBX receives a challenge format it supports.

One-way audio usually happens when a firewall blocks RTP media ports or when NAT advertises an unreachable private IP address in the session description. Verify that your firewall allows the required media ports, configure NAT traversal or public media addressing on your PBX, and confirm both sides share a supported audio codec.

Yes, when you configure TLS transport on port 5061 to encrypt SIP signaling in transit. Unencrypted UDP and TCP signaling are also available on port 5060 for equipment that requires them.

Bird signs webhook requests with an HMAC signature. Validate the request signature against your endpoint's signing secret before processing the event payload, and rotate the signing secret from the dashboard whenever needed.

Voice call records are stored in your workspace's configured service region. Review Bird's data-processing and retention terms for full details on regional media handling, signaling, and storage locations.

Permissions are separated by role: voice write access allows an authorized key to authenticate SIP calls on trunks where it is assigned, voice read access permits reading call logs, and a separate voice management permission controls trunk and routing configuration.

Bird writes the detailed rejection reason to your private dashboard call log while returning a generic service-unavailable response over SIP. Keeping detailed refusal reasons off the signaling response prevents outside scanners from probing your trunk to discover valid numbers, credentials, or enabled destinations.

Security certifications and compliance reports are available in the Bird Trust Center at trust.bird.com, and our data processing agreement, privacy statement, and acceptable use policy are published at bird.com/legal. Contact your Bird account team if you need assistance with a custom vendor security review.

A call sequence controls what happens inside a live phone call, such as playing prompts, collecting keypad digits, and recording audio. An automation flow coordinates broader multi-step business workflows across channels, and each is published independently.

Yes. You can play a text-to-speech or pre-recorded audio prompt, collect keypad presses, and route callers down separate branches for valid selections, timeouts, or unrecognized digits.

No. Call sequence input collection reads DTMF keypad digits pressed by the caller. Spoken natural-language conversations use an AI voice runtime with speech recognition and turn-taking.

Calls already running on a published version finish on that snapshot without interruption, while new calls pick up the newly published version. Draft test calls evaluate the latest saved steps as they move from one node to the next.

No. An accepted request confirms that Bird queued the call attempt for dialing. Track the call's lifecycle events and call record to see whether the recipient answered, and use idempotency keys on retries to prevent duplicate calls.

No. A phone menu follows predefined choices such as keypad digits. An AI voice conversation interprets language and generates responses through a conversational runtime. Both still need a complete call-routing and outcome-handling design.

A SIP-capable runtime can connect through Bird when its signaling, authentication and media behavior are compatible. Validate the integration with a real call in both directions before moving traffic.

No. MCP lets an authorized software agent operate account tools. A live voice agent additionally needs audio, speech processing, turn-taking and a conversation application.

Connect those actions through your application’s authorized tools. Treat their returned status as the source of truth, and require the appropriate customer confirmation before making a change.

Measure call connection and completion separately from task success. Track the confirmed business result, escalation rate and observed failure reasons; a transcript or an answered call alone cannot prove conversion.

No. Newly provisioned numbers default to a rejecting route until you assign an inbound destination such as a SIP trunk or a forwarding number.

Yes. Point the phone number's inbound route to the SIP trunk and delivery gateway where your AI voice runtime listens, so incoming callers connect directly to your assistant.

Check both the inbound leg and the correlated outbound forwarding leg in the call log. A forwarded call requires a verified target number, an enabled destination country, active carrier routing, and available concurrency and spend capacity.

No. The route field shows which routing rule Bird selected for the incoming call. Check the call status and lifecycle events to confirm whether the destination answered.

Forwarding bridges an incoming call leg with a new outbound call leg to your forwarding number. Review the published rates for both legs and inspect the call log for the rated charges.

No. The built-in dashboard phone runs in your web browser over WebRTC and connects through your workspace's configured Bird SIP trunk.

Yes. Route a number to a ring group, and the phone rings for the group's members who are online in the dashboard. The first member to select Accept takes the call. You can also route incoming calls to your SIP PBX, a published call sequence, or a verified phone number.

Yes. Choose Online or Busy in the phone's status before you dial. Busy lets you keep placing calls without being rung for incoming ones.

By default, up to 10 users in an organization can be online in the phone at a time in each region, and the limit depends on your Voice plan. A user who is online in several workspaces counts once.

Yes. Use the on-screen dialpad during an active call to send DTMF keypad tones for navigating IVR menus or entering extensions.

No. Browser calls use the same per-destination Voice rates and billing increments as SIP trunk calls, and their final rated cost appears on the call record.

No. Bird Voice does not support emergency calling, so use a local telephone service for emergency numbers.

No. Recording happens when you enable it in your call workflow or sequence, giving you control over which calls are captured and when recording starts and stops.

No. Audio recording and speech-to-text transcription are configured separately, so you can record audio on its own or request transcription when you need searchable text.

Yes. Transcription processing finishes asynchronously after the call disconnects, so track the call outcome and the transcript status separately.

No. A single session can span multiple call legs, such as an inbound call and a transferred leg, and each leg can produce its own recording and transcript.

A transcript provides a record of what was said during the conversation. Verify completed bookings, order updates, or payments directly against the system of record that processed the transaction.