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Cloud Voice Documentation

Create a SIP Peer Trunk

A SIP (Session Initiation Protocol) peer trunk links your phone system, also called the PBX (private branch exchange), to an internet telephony service provider (ITSP) that identifies your system by its domain name or IP address rather than by a login. Use this type of trunk when the provider gives you connection details but no account credentials. The steps below walk through a typical setup that applies to any peer trunk.

Before you start

Section titled “Before you start”

This example assumes you have a SIP service from an ITSP called ABC with the following details:

  • Provider domain: abc.provider.com
  • Protocol: SIP
  • Registration port: 5060
  • Transport: UDP (User Datagram Protocol)

Make sure the following are true before you begin:

  • You have a SIP service from an ITSP that supplies a domain name or IP address only, with no username or password.
  • Your phone system can reach the ITSP over the network.
  • Your account can add trunks.

Add the trunk

Section titled “Add the trunk”

  1. Sign in to the phone system web portal and go to Extension and Trunk > Trunk, then click Add.

  2. In the Basic section, fill in these fields:

    • Name: A label that helps you recognize the trunk.
    • Trunk Status: Choose Enabled.
    • Select ITSP Template: Choose General.

  3. In the Detailed Configuration section, pick the trunk type and enter the SIP details your ITSP provided.

    • Trunk Type: Choose the peer trunk option that matches how your provider routes calls:

      • Peer Trunk (DID Based): Use this when the ITSP routes calls by DID number. DID (Direct Inward Dialing) is a phone number that connects an outside caller straight to a specific trunk or extension.
      • Peer Trunk (Port Based): Use this when the ITSP routes calls by SIP registration port.
      • Peer Trunk (Private Network): Use this when the ITSP and the phone system share the same private network.

      After you select a type, the phone system shows its own Static IP Address and Port on the page.

    • Transport: Select the transport your ITSP uses. In this example, choose UDP.

    • Hostname/IP: Enter the ITSP domain name or IP address. In this example, enter abc.provider.com.

    • Port: Enter the registration port your provider gave you. In this example, enter 5060.

    • Domain: Enter the domain used in the SIP URI (Uniform Resource Identifier, the address of a SIP endpoint) of headers such as From and To. In this example, enter abc.provider.com.

  4. Optional: If you bought DID numbers from the ITSP, open the DIDs/DDIs tab to add them to the trunk. (DDI, or Direct Dialing Inward, is the term used outside North America for a DID.)

    a. Click Add, then enter your DID numbers.

    • To add one number, set Create Method to Single DID, then configure:
      • DID/DDI: The DID number from your provider.
      • DID/DDI Name: Optional. A label that distinguishes inbound calls by DID number. When someone dials the number, this name appears on the called party’s device.
    • To add a block of numbers, set Create Method to DID Range, then configure:
      • DID Range: The first and last numbers in the range.
      • DID/DDI Name: Optional. A label that distinguishes inbound calls by DID number. When someone dials the number, this name appears on the called party’s device.

    b. Click Confirm.

  5. Click Save, then Apply.

Check the result

Section titled “Check the result”

Go to Extension and Trunk > Trunk and review the trunk status on the trunk list.

If the status shows Registered trunk indicator, the trunk registered successfully.

For an explanation of every trunk state, see SIP Trunk status.

Next steps

Section titled “Next steps”