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Overview

Bland supports inbound SIP termination, allowing customers to direct calls from their SIP provider to Bland for handling.

This guide provides:

  • SIP connection details
  • Requirements and security settings
  • Instructions for attaching, updating, and detaching SIP routes via Bland’s API
  • Schema definitions and usage patterns

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Entitlement Requirement

All /sip endpoints are protected by an entitlement check.

Your organization must have the SIP entitlement enabled to use SIP features. If not, all requests to the /sip routes will return:

{
  "data": null,
  "errors": [
    {
      "error": "SIP_NOT_ENABLED",
      "message": "SIP is not enabled for this organization"
    }
  ]
}

Contact support to have SIP enabled for your Enterprise organization.

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SIP Termination Details

SIP Signaling Endpoint:

us1.sip.bland.ai:5061;transport=tls

Static IP Addresses of the SIP Signalling Server(s):

35.80.235.26
54.189.4.67

Supported Codecs:

  • Currently Supported: PCMU, PCMA
  • Coming Soon: Opus, G722

Security Requirements:

  • SIP Signaling: TLS 1.2 or higher
  • RTP Media: SRTP using AES_CM_128_HMAC_SHA1_80

Other Configurations:

  • RTCP: Uses port RTP + 1

  • DTMF: RFC 2833 (Out-of-band via RTP payload)

  • Number Format: +E.164 or E.164 (both supported for origination and termination)

  • SIP Registration: Not required (Bland determines routing based on predefined configurations)

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API Reference

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Attach SIP Endpoint

POST /sip/attach

Attach a SIP configuration to a phone number.

​
phone_number
string

The phone number to associate with the SIP configuration. Must be in E.164 format.

​
directions
array

An array of directions for the SIP routing. Valid values: inbound, outbound. If outbound, you must also provide a sip_endpoint.

​
service
string

Must be set to sip.

Example Request
curl -X POST https://api.bland.ai/v1/sip/attach \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+14150000000",
    "directions": [
      { "type": "inbound" }
      { "type": "outbound", "sip_endpoint": "sip.customer.com" } // Either inbound or outbound can be provided
    ],
    "service": "sip"
  }'

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Update SIP Direction

POST /sip/update

Update a phone number’s SIP routing direction.

​
phone_number
string

The phone number for which to update the direction.

​
updates
object

The updated direction object. Use type: outbound and provide sip_endpoint, or type: inbound.

Example Request
curl -X POST https://api.bland.ai/v1/sip/update \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+14150000000",
    "updates": {
      "type": "outbound",
      "sip_endpoint": "sip:user@your.provider.com"
    }
  }'

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Detach SIP Endpoint

POST /sip/detach

Remove SIP configuration from a number.

​
phone_number
string

The phone number to detach SIP routing from.

​
directions
array

Direction(s) to remove. Either inbound or outbound.

​
service
string

Must be set to sip.

Example Request
curl -X POST https://api.bland.ai/v1/sip/detach \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+14150000000",
    "directions": [
      { "type": "inbound" }
    ],
    "service": "sip"
  }'

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Get SIP Config

GET /sip?inbound_id={inbound_id}

Returns current SIP configuration (if any) for a given inbound_id.

​
inbound_id
number

(Optional) The ID of the inbound number to fetch SIP configuration for.

Example Request
curl -X GET 'https://api.bland.ai/v1/sip?inbound_id=12345' \
  -H "Authorization: Bearer <token>"

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Example Response

{
  "data": {
    "phone_number": "+14150000000",
    "directions": [ "inbound" ]
  },
  "errors": null
}

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Notes

  • SIP media handling currently supports inbound-only termination.
  • Phone numbers can be attached independently for inbound and outbound routing via the API.
  • All requests must conform to the expected schema; invalid payloads will be rejected with a 400 response.
  • Each API response includes a success status and, if applicable, an error message to aid debugging.