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SIP lets you bring your own carrier. Calls from your carrier, PBX, or contact center reach a Bland agent, and the agent places calls out through your SIP provider. You create a trunk, attach your numbers to it, and assign each number an agent.
SIP is organization scope only. Inside a single agent there is no Phone numbers item. Switch the selector at the top of the sidebar to All agents first.

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Where SIP lives

At All agents, go to Dispatch, then Phone numbers, then the SIP tab. It lists your trunks, and Create trunk and Port a number sit at the top right. Each trunk has its own page with three tabs:
  • Overview: call volume, answer rate, and the call log with each call’s SIP trace
  • Numbers: the numbers and DIDs attached to the trunk
  • Configure: the trunk’s endpoint, authentication, headers, and firewall details

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How it works

  • A trunk holds the connection to your SIP infrastructure: the endpoint, transport, and authentication. You set it up once.
  • Numbers and DIDs attach to a trunk and inherit its settings. Each one can route inbound, outbound, or both. E.164 numbers, DIDs, and extensions are all supported.
  • SIP headers become variables. Every X- header your PBX sends reaches the agent as {{sip_header_<name>}}, and Bland can send call data back in headers. See SIP headers.
  • Signaling runs over TLS on port 5061, and audio over SRTP. Bland does not accept plain UDP or port 5060.

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Prerequisites

  • A carrier, PBX, or SBC that supports TLS signaling and SRTP media
  • The numbers you will route, on your own carrier. Numbers bought from Bland can’t be attached to a trunk
  • Access to your firewall, to allow-list Bland’s signaling and media IPs

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Connect your carrier

1

Create a trunk

On the SIP tab, press Create trunk and follow the setup wizard. For Bandwidth, Twilio, Telnyx, 3CX, Five9, or NICE CXone, follow that provider’s guide under SIP integrations in the sidebar instead.
2

Attach your numbers

Add the numbers or DIDs that route through the trunk, on the wizard’s last step or the trunk’s Numbers tab.
3

Assign an agent

Under Phone numbers, press Configure on the number and pick the agent under Assignment.
4

Place a test call

Call the number from a phone to test inbound. For outbound, use the number as from:
You know it worked when the call shows up on the trunk’s Overview tab.

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API

Every SIP endpoint is under /v1/sip and authenticates with your API key. Parameters for each endpoint are in the API reference.

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Next steps

Set up a trunk

Walk through the setup wizard step by step.

Transfers

Send callers to a DID, extension, or SIP URI.

SIP headers

Use your PBX’s headers as agent variables.

Network and security

Regions, IPs to allow-list, and TLS and SRTP.
Docs for agents: llms.txt