How to configure SIP Trunks on 3CX

You’ll learn how to configure your 3CX PBX to make use of our SIP-trunk services and inbound numbers.

Step one

Create a SIP-trunk at MessageBird Dashboard and make sure that you have a Domain name with an attached ACL that only includes IP-addresses. When an ACL includes username/passwords, they are obligated to use for setting up a SIP-trunk. For a detailed guide, head to this article: SIP Trunking.

Step two

Log in to the management interface of your 3CX and do the following:

Go to SIP trunks:

  • Select ‘Add SIP trunk’

  • ‘Select Country’: choose ‘Generic’

  • ‘Select Provider’: pick ‘Generic VoiP Provider’

  • ‘Main Trunk No’: enter your default number that you want to display, in the international format including a leading + sign. For example +31123456789

  • Click the ‘Ok’ button when ready.

Go to the tab page General:

  • Enter a name for your Trunk. This is for your reference only, so pick a name that will be easily identifiable for you.

  • Registrar/Server/Gateway Hostname or IP’: enter the domain name that you created at the MessageBird portal

  • ‘Outbound Proxy’: enter the domain name that you created at the MessageBird portal again

  • ‘Type of Authentication’: this can stay on ‘Do not require - IP Based'

  • ‘Authentication ID’ (SIP User ID): leave it empty.

  • ‘Authentication Password’: leave it empty.

  • ‘3 Way Authentication Password’: don’t set.

Keep in mind that other settings can be changed based on your own preference. Click the ‘Ok’ button when ready.

Go to the tab page DIDs:

  • Click ‘Add DID’ and enter your DID in international format Without a leading + sign (for example 31123456789) and repeat for all your DIDs. Click the ‘Ok’ button when ready.

Go to the tab page Caller ID:

  • At the selection Outbound add 2 replacement rules click ‘Add’

  • Source Pattern 0 and Replace Pattern 31

  • Source Pattern 00 and Replace Pattern +

  • Click the ‘Ok’ button when ready.

Go to the tab page Options:

  • At selection ‘Advanced’, select ‘Support Re-invite’, and disable ‘Force invites to be sent to IP of Registar’

  • At selection ‘Codec Priority’, remove the codec G729

  • Click the ‘Ok’ button when ready.

* You don’t need to change anything on tab page Inbound Parameters.

Go to the tab page Outbound Parameters:

  • By default the Caller ID from Extension settings are used in case of Call forwarding to outbound calls; however, in case you want to see the original caller ID of the dialler with ‘Call Forwarding’, you need to change the following details:

    • Change Display Name to ‘Originator Caller number will be sent’

    • Change User Part change to ‘Originator Caller number will be sent’

  • Click the ‘Ok’ button after making these changes.

That’s it! You’re all set and ready.

Check out this additional information if you need it:

  • Additional information for Outbound Rules (general settings)

  • Additional information for Inbound Rules (general settings)

  • Additional information for Extensions (general settings)

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