# 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.\ <br>

**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.](https://support.messagebird.com/hc/en-us/articles/360001836358)\ <br>

**Step two**

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

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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.

<figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-4f6143ee314455dc0346b204b0ded4cc5e78d1df%2Fimage4.png?alt=media" alt=""><figcaption></figcaption></figure>

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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.\ <br>

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

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.\ <br>

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.\ <br>

<figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-86111c05f0bf41791c23a7d575ca33b328082c04%2Fimage3.png?alt=media" alt=""><figcaption></figcaption></figure>

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.\
  \ <br>

  <figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-5fd96cb556cc716792b4f2283d04ca85cf31a6ab%2Fimage1.png?alt=media" alt=""><figcaption></figcaption></figure>

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\* You don’t need to change anything on tab page **Inbound Parameters.**<br>

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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:&#x20;
  * 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.

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That’s it! You’re all set and ready.

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Check out this additional information if you need it:

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* Additional information for *Outbound Rules* (general settings)\ <br>

  <figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-cad526c8e6fb3063a87e31467cc897e9d70ac24d%2Fimage6.png?alt=media" alt=""><figcaption></figcaption></figure>

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* Additional information for *Inbound Rules* (general settings)\ <br>

  <figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-687e304d05bc71c0d2a5bcaf1eb2ff3ea24515fb%2Fimage2.png?alt=media" alt=""><figcaption></figcaption></figure>

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* Additional information for *Extensions* (general settings)\ <br>

  <figure><img src="https://675349995-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUJNEE9TMK4fU91VKstBr%2Fuploads%2Fgit-blob-aa00aa39757bd2f239f0bba7429cbeb1e5439faf%2Fimage5.png?alt=media" alt=""><figcaption></figcaption></figure>

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