# Telnyx Calling: SIP Trunking — Documentation Index
> SIP Trunking documentation within the Calling section of the Telnyx developer docs (https://developers.telnyx.com).
> Root index: https://developers.telnyx.com/llms.txt · Calling index: https://telnyx-openapi-ng.s3.us-east-1.amazonaws.com/llms/calling.txt · Full content for this subsection: https://telnyx-openapi-ng.s3.us-east-1.amazonaws.com/llms/calling/sip-trunking-full.txt

## Getting Started

- [Overview](https://developers.telnyx.com/docs/voice/sip-trunking/get-started.md): Overview of Telnyx SIP Trunking — buy numbers, create a SIP connection, configure authentication and routing, and place your first inbound/outbound call.

## Authentication

- [Overview](https://developers.telnyx.com/docs/voice/sip-trunking/authentication/credential-types.md): SIP authentication methods supported by Telnyx SIP Trunking — credential, IP, FQDN, and token authentication. Compare and choose the right method.
- [IP Authentication Token](https://developers.telnyx.com/docs/voice/sip-trunking/authentication/ip-authentication-token.md): Use IP authentication tokens on Telnyx SIP Trunking to authenticate calls without a fixed allowlist. Generate tokens and include them in SIP INVITEs.
- [Tech Prefix](https://developers.telnyx.com/docs/voice/sip-trunking/authentication/tech-prefix.md): Authenticate Telnyx SIP Trunking calls with a tech prefix. Prepend a numeric prefix to the request URI to identify your account on outbound INVITEs.

## Configuration

- [Caller ID Policy](https://developers.telnyx.com/docs/voice/sip-trunking/configuration/caller-id-policy.md): Configure caller ID policy on Telnyx SIP Trunking connections. Allow, override, or block From and P-Asserted-Identity values on outbound calls.
- [Concurrent Call Limits](https://developers.telnyx.com/docs/voice/sip-trunking/configuration/concurrent-limits.md): Set concurrent call limits on Telnyx SIP Trunking connections. Cap inbound and outbound channels per connection to protect capacity and control spend.
- [P-Charge-Info](https://developers.telnyx.com/docs/voice/sip-trunking/configuration/p-charge-info-header.md): Use the P-Charge-Info SIP header on Telnyx SIP Trunking to specify the billed number for outbound calls. Includes header format and behavior rules.
- [Outbound Voice Profiles for SIP trunking](https://developers.telnyx.com/docs/voice/sip-trunking/configuration/outbound-voice-profiles.md): Attach Outbound Voice Profiles to Telnyx SIP Trunking connections to control allowed destinations, rate limits, daily spend, and outbound routing.

## Routing

- [Round Robin Routing](https://developers.telnyx.com/docs/voice/sip-trunking/routing/round-robin-routing.md): Distribute Telnyx SIP Trunking traffic evenly across multiple destinations using round-robin routing. Spread load between PBXes or geographic regions.
- [AnchorSite](https://developers.telnyx.com/docs/voice/sip-trunking/routing/anchorsite-configuration.md): Configure AnchorSite to control which Telnyx PoP handles media routing for SIP calls, with latency-based and manual selection modes.
- [Failover & Retries](https://developers.telnyx.com/docs/voice/sip-trunking/routing/failover-and-retries.md): Configure failover and retry behavior on Telnyx SIP Trunking. Route calls to backup destinations on SIP failure codes for high availability.

## Network Configuration

- [IP Whitelisting](https://developers.telnyx.com/docs/voice/sip-trunking/network-configuration/ip-whitelisting.md): Whitelist your IP addresses on Telnyx SIP Trunking connections to authenticate calls without credentials. Includes allowed CIDR ranges and edge IPs.
- [SRV Records](https://developers.telnyx.com/docs/voice/sip-trunking/network-configuration/srv-records.md): Use SRV records to route SIP traffic to Telnyx with automatic failover. Configure DNS for sip._udp / sip._tcp and let your PBX resolve Telnyx edges.
- [STUN/TURN](https://developers.telnyx.com/docs/voice/sip-trunking/network-configuration/stun-turn-servers.md): Connect WebRTC and NAT-traversed SIP clients to Telnyx using STUN and TURN servers. Includes hostnames, ports, and authentication for media relays.

## Features

- [Noise Suppression](https://developers.telnyx.com/docs/voice/sip-trunking/features/noise-suppression.md): Enable AI noise suppression on Telnyx SIP Trunking calls. Remove background noise from inbound or outbound audio for clearer phone conversations.
- [Jitter Buffer](https://developers.telnyx.com/docs/voice/sip-trunking/features/jitter-buffer.md): Configure the adaptive jitter buffer on Telnyx SIP Trunking to smooth out RTP packet delay and improve voice quality on lossy or variable networks.
- [External Transfers](https://developers.telnyx.com/docs/voice/sip-trunking/features/external-transfers.md): Use SIP REFER to transfer Telnyx SIP Trunking calls to external numbers. Configure your PBX or Voice API to hand off calls without bridging media.
- [SIP URI Calling](https://developers.telnyx.com/docs/voice/sip-trunking/features/sip-uri-calling.md): Place and receive SIP URI calls over Telnyx SIP Trunking. Dial endpoints by sip:user@domain instead of E.164 to connect VoIP systems directly.

## STIR/SHAKEN

- [Attestation Behavior](https://developers.telnyx.com/docs/voice/stir-shaken/attestation-behavior.md): How Telnyx assigns STIR/SHAKEN attestation levels (A, B, C) to outbound calls. Understand the criteria, signed identity headers, and downstream impact.
- [Hosted Certificate](https://developers.telnyx.com/docs/voice/stir-shaken/hosted-cert.md): Use a Telnyx hosted STIR/SHAKEN certificate to sign outbound calls without managing your own CA. Includes setup, certificate rotation, and verification.
- [SIP Header Parameters](https://developers.telnyx.com/docs/voice/stir-shaken/sip-header-parameters.md): Reference of STIR/SHAKEN SIP header parameters used by Telnyx — Identity, attest, origid, dest, and how to read and verify a signed identity header.

## Emergency Calling

- [Dynamic E911](https://developers.telnyx.com/docs/voice/sip-trunking/emergency-calling-dynamic-e911.md): Provision Dynamic E911 on Telnyx SIP Trunking for VoIP emergency calling. Register caller locations dynamically and route 911 calls to the correct PSAP.

## Troubleshooting

- [Response Codes](https://developers.telnyx.com/docs/voice/sip-trunking/troubleshooting/response-codes.md): Reference of SIP response codes you'll see on Telnyx SIP Trunking calls — 4xx client errors, 5xx server errors, 6xx global failures, and what they mean.

## SIP Integrations Guides

- [Configuration Overview](https://developers.telnyx.com/docs/voice/sip-trunking/configuration-guides.md): Telnyx's SIP trunking guide will help you configure your sip
- [LiveKit](https://developers.telnyx.com/docs/voice/sip-trunking/livekit-configuration-guide.md): Integrate Telnyx SIP Trunks with LiveKit for real-time audio and video applications. Includes Telnyx configuration and LiveKit SIP gateway setup steps.

## API Reference (SIP Trunking)

### Connections

- [List connections](https://developers.telnyx.com/api-reference/connections/list-connections.md): Returns a list of your connections irrespective of type.
- [Retrieve a connection](https://developers.telnyx.com/api-reference/connections/retrieve-a-connection.md): Retrieves the high-level details of an existing connection. To retrieve specific authentication information, use the endpoint for the specific connection type.

### Credential Connections

- [List credential connections](https://developers.telnyx.com/api-reference/credential-connections/list-credential-connections.md): Returns a list of your credential connections.
- [Create a credential connection](https://developers.telnyx.com/api-reference/credential-connections/create-a-credential-connection.md): Creates a credential connection.
- [Retrieve a credential connection](https://developers.telnyx.com/api-reference/credential-connections/retrieve-a-credential-connection.md): Retrieves the details of an existing credential connection.
- [Update a credential connection](https://developers.telnyx.com/api-reference/credential-connections/update-a-credential-connection.md): Updates settings of an existing credential connection.
- [Delete a credential connection](https://developers.telnyx.com/api-reference/credential-connections/delete-a-credential-connection.md): Deletes an existing credential connection.
- [Check a Credential Connection Registration Status](https://developers.telnyx.com/api-reference/credential-connections/check-a-credential-connection-registration-status.md): Checks the registration_status for a credential connection, (`registration_status`) as well as the timestamp for the last SIP registration event (`registration…

### IPs

- [List Ips](https://developers.telnyx.com/api-reference/ips/list-ips.md): Get all IPs belonging to the user that match the given filters.
- [Create an Ip](https://developers.telnyx.com/api-reference/ips/create-an-ip.md): Create a new IP object.
- [Retrieve an Ip](https://developers.telnyx.com/api-reference/ips/retrieve-an-ip.md): Return the details regarding a specific IP.
- [Update an Ip](https://developers.telnyx.com/api-reference/ips/update-an-ip.md): Update the details of a specific IP.
- [Delete an Ip](https://developers.telnyx.com/api-reference/ips/delete-an-ip.md): Delete an IP.

### IP Connections

- [List Ip connections](https://developers.telnyx.com/api-reference/ip-connections/list-ip-connections.md): Returns a list of your IP connections.
- [Create an Ip connection](https://developers.telnyx.com/api-reference/ip-connections/create-an-ip-connection.md): Creates an IP connection.
- [Retrieve an Ip connection](https://developers.telnyx.com/api-reference/ip-connections/retrieve-an-ip-connection.md): Retrieves the details of an existing ip connection.
- [Update an Ip connection](https://developers.telnyx.com/api-reference/ip-connections/update-an-ip-connection.md): Updates settings of an existing IP connection.
- [Delete an Ip connection](https://developers.telnyx.com/api-reference/ip-connections/delete-an-ip-connection.md): Deletes an existing IP connection.

### FQDNs

- [List FQDNs](https://developers.telnyx.com/api-reference/fqdns/list-fqdns.md): Get all FQDNs belonging to the user that match the given filters.
- [Create an FQDN](https://developers.telnyx.com/api-reference/fqdns/create-an-fqdn.md): Create a new FQDN object.
- [Retrieve an FQDN](https://developers.telnyx.com/api-reference/fqdns/retrieve-an-fqdn.md): Return the details regarding a specific FQDN.
- [Update an FQDN](https://developers.telnyx.com/api-reference/fqdns/update-an-fqdn.md): Update the details of a specific FQDN.
- [Delete an FQDN](https://developers.telnyx.com/api-reference/fqdns/delete-an-fqdn.md): Delete an FQDN.

### FQDN Connections

- [List FQDN connections](https://developers.telnyx.com/api-reference/fqdn-connections/list-fqdn-connections.md): Returns a list of your FQDN connections.
- [Create an FQDN connection](https://developers.telnyx.com/api-reference/fqdn-connections/create-an-fqdn-connection.md): Creates a FQDN connection.
- [Retrieve an FQDN connection](https://developers.telnyx.com/api-reference/fqdn-connections/retrieve-an-fqdn-connection.md): Retrieves the details of an existing FQDN connection.
- [Update an FQDN connection](https://developers.telnyx.com/api-reference/fqdn-connections/update-an-fqdn-connection.md): Updates settings of an existing FQDN connection.
- [Delete an FQDN connection](https://developers.telnyx.com/api-reference/fqdn-connections/delete-an-fqdn-connection.md): Deletes an FQDN connection.

### UAC Connections

- [List UAC connections](https://developers.telnyx.com/api-reference/uac-connections/list-uac-connections.md): Returns a list of your UAC connections. A UAC (User Agent Client) Connection registers Telnyx to your PBX — the opposite of a standard SIP trunk, where the PBX…
- [Create a UAC connection](https://developers.telnyx.com/api-reference/uac-connections/create-a-uac-connection.md): Creates a UAC connection. A UAC (User Agent Client) Connection registers Telnyx to your PBX — the opposite of a standard SIP trunk, where the PBX registers to…
- [Retrieve a UAC connection](https://developers.telnyx.com/api-reference/uac-connections/retrieve-a-uac-connection.md): Retrieves the details of an existing UAC connection.
- [Update a UAC connection](https://developers.telnyx.com/api-reference/uac-connections/update-a-uac-connection.md): Updates settings of an existing UAC connection.
- [Delete a UAC connection](https://developers.telnyx.com/api-reference/uac-connections/delete-a-uac-connection.md): Deletes an existing UAC connection.
- [Check a UAC Connection Registration Status](https://developers.telnyx.com/api-reference/uac-connections/check-a-uac-connection-registration-status.md): Checks the registration status for a UAC connection (`registration_status`) as well as the timestamp for the last SIP registration event (`registration_status_…

### Outbound Voice Profiles

- [Get all outbound voice profiles](https://developers.telnyx.com/api-reference/outbound-voice-profiles/get-all-outbound-voice-profiles.md): Get all outbound voice profiles belonging to the user that match the given filters.
- [Create an outbound voice profile](https://developers.telnyx.com/api-reference/outbound-voice-profiles/create-an-outbound-voice-profile.md): Create an outbound voice profile.
- [Retrieve an outbound voice profile](https://developers.telnyx.com/api-reference/outbound-voice-profiles/retrieve-an-outbound-voice-profile.md): Retrieves the details of an existing outbound voice profile.
- [Updates an existing outbound voice profile.](https://developers.telnyx.com/api-reference/outbound-voice-profiles/updates-an-existing-outbound-voice-profile.md): Updates an existing outbound voice profile.
- [Delete an outbound voice profile](https://developers.telnyx.com/api-reference/outbound-voice-profiles/delete-an-outbound-voice-profile.md): Deletes an existing outbound voice profile.

### Dialogflow Integration

- [Retrieve stored Dialogflow Connection](https://developers.telnyx.com/api-reference/dialogflow-integration/retrieve-stored-dialogflow-connection.md): Return details of the Dialogflow connection associated with the given CallControl connection.
- [Create a Dialogflow Connection](https://developers.telnyx.com/api-reference/dialogflow-integration/create-a-dialogflow-connection.md): Save Dialogflow Credentiails to Telnyx, so it can be used with other Telnyx services.
- [Update stored Dialogflow Connection](https://developers.telnyx.com/api-reference/dialogflow-integration/update-stored-dialogflow-connection.md): Updates a stored Dialogflow Connection.
- [Delete stored Dialogflow Connection](https://developers.telnyx.com/api-reference/dialogflow-integration/delete-stored-dialogflow-connection.md): Deletes a stored Dialogflow Connection.

### External Connections

- [List all External Connections](https://developers.telnyx.com/api-reference/external-connections/list-all-external-connections.md): This endpoint returns a list of your External Connections inside the 'data' attribute of the response. External Connections are used by Telnyx customers to sea…
- [Creates an External Connection](https://developers.telnyx.com/api-reference/external-connections/creates-an-external-connection.md): Creates a new External Connection based on the parameters sent in the request. The external_sip_connection and outbound voice profile id are required. Once cre…
- [Retrieve an External Connection](https://developers.telnyx.com/api-reference/external-connections/retrieve-an-external-connection.md): Return the details of an existing External Connection inside the 'data' attribute of the response.
- [Update an External Connection](https://developers.telnyx.com/api-reference/external-connections/update-an-external-connection.md): Updates settings of an existing External Connection based on the parameters of the request.
- [Deletes an External Connection](https://developers.telnyx.com/api-reference/external-connections/deletes-an-external-connection.md): Permanently deletes an External Connection. Deletion may be prevented if the application is in use by phone numbers, is active, or if it is an Operator Connect…
- [List all civic addresses and locations](https://developers.telnyx.com/api-reference/external-connections/list-all-civic-addresses-and-locations.md): Returns the civic addresses and locations from Microsoft Teams.
- [Retrieve a Civic Address](https://developers.telnyx.com/api-reference/external-connections/retrieve-a-civic-address.md): Return the details of an existing Civic Address with its Locations inside the 'data' attribute of the response.
- [Update a location's static emergency address](https://developers.telnyx.com/api-reference/external-connections/update-a-locations-static-emergency-address.md)
- [List all phone numbers](https://developers.telnyx.com/api-reference/external-connections/list-all-phone-numbers.md): Returns a list of all active phone numbers associated with the given external connection.
- [Retrieve a phone number](https://developers.telnyx.com/api-reference/external-connections/retrieve-a-phone-number.md): Return the details of a phone number associated with the given external connection.
- [Update a phone number](https://developers.telnyx.com/api-reference/external-connections/update-a-phone-number.md): Asynchronously update settings of the phone number associated with the given external connection.
- [List all Releases](https://developers.telnyx.com/api-reference/external-connections/list-all-releases.md): Returns a list of your Releases for the given external connection. These are automatically created when you change the `connection_id` of a phone number that i…
- [Retrieve a Release request](https://developers.telnyx.com/api-reference/external-connections/retrieve-a-release-request.md): Return the details of a Release request and its phone numbers.
- [List all Upload requests](https://developers.telnyx.com/api-reference/external-connections/list-all-upload-requests.md): Returns a list of your Upload requests for the given external connection.
- [Creates an Upload request](https://developers.telnyx.com/api-reference/external-connections/creates-an-upload-request.md): Creates a new Upload request to Microsoft teams with the included phone numbers. Only one of civic_address_id or location_id must be provided, not both. The ma…
- [Refresh the status of all Upload requests](https://developers.telnyx.com/api-reference/external-connections/refresh-the-status-of-all-upload-requests.md): Forces a recheck of the status of all pending Upload requests for the given external connection in the background.
- [Get the count of pending upload requests](https://developers.telnyx.com/api-reference/external-connections/get-the-count-of-pending-upload-requests.md): Returns the count of all pending upload requests for the given external connection.
- [Retrieve an Upload request](https://developers.telnyx.com/api-reference/external-connections/retrieve-an-upload-request.md): Return the details of an Upload request and its phone numbers.
- [Retry an Upload request](https://developers.telnyx.com/api-reference/external-connections/retry-an-upload-request.md): If there were any errors during the upload process, this endpoint will retry the upload request. In some cases this will reattempt the existing upload request,…
- [List all log messages](https://developers.telnyx.com/api-reference/external-connections/list-all-log-messages.md): Retrieve a list of log messages for all external connections associated with your account.
- [Retrieve a log message](https://developers.telnyx.com/api-reference/external-connections/retrieve-a-log-message.md): Retrieve a log message for an external connection associated with your account.
- [Dismiss a log message](https://developers.telnyx.com/api-reference/external-connections/dismiss-a-log-message.md): Dismiss a log message for an external connection associated with your account.
- [Refresh Operator Connect integration](https://developers.telnyx.com/api-reference/external-connections/refresh-operator-connect-integration.md): This endpoint will make an asynchronous request to refresh the Operator Connect integration with Microsoft Teams for the current user. This will create new ext…

### Call Recordings

- [List all call recordings](https://developers.telnyx.com/api-reference/call-recordings/list-all-call-recordings.md): Returns a list of your call recordings.
- [Retrieve a call recording](https://developers.telnyx.com/api-reference/call-recordings/retrieve-a-call-recording.md): Retrieves the details of an existing call recording.
- [Delete a call recording](https://developers.telnyx.com/api-reference/call-recordings/delete-a-call-recording.md): Permanently deletes a call recording.
- [Delete a list of call recordings](https://developers.telnyx.com/api-reference/call-recordings/delete-a-list-of-call-recordings.md): Permanently deletes a list of call recordings.
- [List all recording transcriptions](https://developers.telnyx.com/api-reference/call-recordings/list-all-recording-transcriptions.md): Returns a list of your recording transcriptions.
- [Retrieve a recording transcription](https://developers.telnyx.com/api-reference/call-recordings/retrieve-a-recording-transcription.md): Retrieves the details of an existing recording transcription.
- [Delete a recording transcription](https://developers.telnyx.com/api-reference/call-recordings/delete-a-recording-transcription.md): Permanently deletes a recording transcription.
- [Retrieve a stored credential](https://developers.telnyx.com/api-reference/call-recordings/retrieve-a-stored-credential.md): Returns the information about custom storage credentials.
- [Create a custom storage credential](https://developers.telnyx.com/api-reference/call-recordings/create-a-custom-storage-credential.md): Creates a custom storage credentials configuration.
- [Update a stored credential](https://developers.telnyx.com/api-reference/call-recordings/update-a-stored-credential.md): Updates a stored custom credentials configuration.
- [Delete a stored credential](https://developers.telnyx.com/api-reference/call-recordings/delete-a-stored-credential.md): Deletes a stored custom credentials configuration.

### Media Storage API

- [List uploaded media](https://developers.telnyx.com/api-reference/media-storage-api/list-uploaded-media.md): Returns a list of stored media files.
- [Upload media](https://developers.telnyx.com/api-reference/media-storage-api/upload-media.md): Upload media file to Telnyx so it can be used with other Telnyx services
- [Retrieve stored media](https://developers.telnyx.com/api-reference/media-storage-api/retrieve-stored-media.md): Returns the information about a stored media file.
- [Update stored media](https://developers.telnyx.com/api-reference/media-storage-api/update-stored-media.md): Updates a stored media file.
- [Deletes stored media](https://developers.telnyx.com/api-reference/media-storage-api/deletes-stored-media.md): Deletes a stored media file.
- [Download stored media](https://developers.telnyx.com/api-reference/media-storage-api/download-stored-media.md): Downloads a stored media file.