# PSTN Trunk PSTN trunks allow you to forward incoming calls through Direct Inward Dialing (DID) to the Public Switched Telephone Network (PSTN). Note Incoming calls forwarded to a PSTN trunk are charged per minute. The rate and availability depend on the destination PSTN phone number. --- ## Create a New PSTN Trunk To create an inbound PSTN trunk, follow these steps: 1. Navigate to the **Voice** section in the left-hand menu. 2. Select **Inbound Trunks** from the submenu. 3. Click the **Create New** button in the top-right corner of the screen. 4. From the dropdown menu, select **PSTN Trunk**. [![Creating a new PSTN Trunk](../../_images/fig175.png)](../../_images/fig175.png) **Fig. 1.** Creating a new PSTN Trunk --- ## Quick PSTN Trunk Configuration Guide To quickly configure a PSTN trunk, enter the required information below: 1. Enter a **Name** - Provide a unique name to identify the trunk. 2. Enter the **PSTN Phone Number** - Specify the destination number in E.164 format (e.g., `12065550100`). 3. Click **Check Rate** and review the displayed per-minute rate. 4. Click the **Create** button to save and activate the configuration. Note The rate and destination availability depend on the PSTN phone number. To review current pricing, see [DIDWW pricelists](../../phone-numbers/buy-numbers/download-pricelists.html#services-coverage-pricing-access-pricelists). [![Quick PSTN trunk configuration with the per-minute rate displayed](../../_images/quick_configuration.png)](../../_images/quick_configuration.png) **Fig. 2.** Quick PSTN trunk configuration --- ## Advanced PSTN Trunk Configuration Guide For advanced configurations, you can customize additional PSTN trunk settings. **General** Configure the destination, capacity, and ringing timeout. [General](#user-panel-pstn-trunk-general-settings) **Number Translations** Configure caller ID filtering using a number list. [Number Translations](#user-panel-pstn-trunk-number-translations) **Trunk Group** Assign trunks to groups for failover and load balancing. [Trunk Group](#user-panel-pstn-trunk-trunk-group-configuration) --- ### General The **General** tab defines the PSTN destination and call limits for the trunk. You can configure the following settings: - **Name** - Enter a unique name to identify the trunk. - **PSTN Phone Number** - Enter the destination number in E.164 format to which calls are forwarded (e.g., `12065550100`). Note Click **Check Rate** to check whether the destination is available and display its per-minute rate. - **Capacity Limit** - Specify the maximum number of simultaneous calls allowed for the trunk. Leave the field set to **Unlimited** to apply no trunk-specific limit. When the limit is reached, the system attempts to route the call through another trunk in the trunk group. - **Ringing Timeout** - Specify the maximum number of seconds to wait for a `200 OK` response after receiving an `18x` response. When the timeout is reached, the routing attempt ends with the **Ringing timeout** disconnect code. [![General tab with PSTN destination, capacity, and ringing timeout settings](../../_images/general1.png)](../../_images/general1.png) **Fig. 3.** General tab --- ### Number Translations The **Number Translations** tab configures caller ID filtering for the PSTN trunk. - **CLI Number List** - Assign a **Number List** to allow or reject incoming calls based on full number matches, prefix matches, or length restrictions. For more information, see the [Number List](number-lists.html#user-panel-voice-in-numberlist) documentation page. [![Number Translations tab with the CLI Number List setting](../../_images/number_translations.png)](../../_images/number_translations.png) **Fig. 4.** Number Translations tab --- ### Trunk Group PSTN Trunk group configuration is **optional** and should only be used when multiple trunks need to be assigned to a single trunk group for **failover** or **load balancing**. You can configure the following settings: - **Trunk Group** - Select the trunk group to assign the trunk to. A trunk can belong to only one trunk group. If no trunk groups exist, see the [Trunk Group Creation Guide](creating-a-new-trunk-group.html#user-panel-trunk-group). - **Priority** - Set the trunk priority within the trunk group. Trunks with lower values are tried first. Trunks with the same priority are ordered by weight. For more details, see [**RFC 2782**](https://datatracker.ietf.org/doc/html/rfc2782.html). - **Weight** - Set the relative weight for trunks with the same priority. A higher value increases the likelihood that the trunk is selected. For more details, see [**RFC 2782**](https://datatracker.ietf.org/doc/html/rfc2782.html). [![Trunk Group tab with trunk group, priority, and weight settings](../../_images/trunk_group.png)](../../_images/trunk_group.png) **Fig. 5.** Trunk Group tab --- ## Edit PSTN Trunk To edit an existing PSTN Trunk, follow these steps: 1. Navigate to the **Voice** section in the left-hand menu. 2. Select **Inbound Trunks** from the submenu. 3. Locate the PSTN trunk that you want to edit and click the [![Actions button](../../_images/three_dots_action_button1.png)](../../_images/three_dots_action_button1.png) button. 4. Click **Edit**. [![Actions Button.](../../_images/edit-trunk.png)](../../_images/edit-trunk.png) **Fig. 6.** Actions Button. 5. In **Edit Inbound PSTN Trunk**, make the required changes and click **Submit** to save them. [![Edit Inbound PSTN Trunk.](../../_images/edit-trunk2.png)](../../_images/edit-trunk2.png) **Fig. 7.** Edit Inbound PSTN Trunk. --- ## Delete PSTN Trunk(s) You can either delete a single PSTN trunk or delete multiple PSTN trunks by using batch actions. Note Trunks assigned to DID numbers or in use cannot be deleted. ### Delete a Single PSTN Trunk To delete an existing PSTN Trunk, follow these steps: 1. Navigate to the **Voice** section in the left-hand menu. 2. Select **Inbound Trunks** from the submenu. 3. Locate the PSTN trunk that you want to delete and click the [![Actions button](../../_images/three_dots_action_button1.png)](../../_images/three_dots_action_button1.png) button. 4. Click **Delete**. [![Actions button with the Delete action selected](../../_images/delete-trunk.png)](../../_images/delete-trunk.png) **Fig. 8.** Actions Button. 5. In the **Delete Trunk(s)** pop-up window, click **Delete** to confirm the trunk deletion. [![Delete Trunk(s) confirmation window.](../../_images/delete21.png)](../../_images/delete21.png) **Fig. 9.** Delete Trunk(s) confirmation window. ### Delete Multiple PSTN Trunks To delete **multiple** existing PSTN Trunks, follow these steps: 1. Navigate to the **Voice** section in the left-hand menu. 2. Select **Inbound Trunks** from the submenu. 3. Select the PSTN trunks you want to delete. 4. Click **Batch Actions** and then select **Delete Trunk(s)**. [![Batch Actions menu with Delete Trunk(s) selected](../../_images/delete-trunks.png)](../../_images/delete-trunks.png) **Fig. 10.** Batch Actions Button. 5. In the **Delete Trunk(s)** pop-up window, click **Delete** to confirm the trunk deletion. [![Delete Trunk(s) confirmation window.](../../_images/delete21.png)](../../_images/delete21.png) **Fig. 11.** Delete Trunk(s) confirmation window. --- ## Additional Information **Assign Trunks to DID Numbers** Learn how to configure DID numbers with trunks and trunk groups for routing inbound calls. [Assign a voice trunk](../../phone-numbers/my-numbers/how-to-guides/assign-voice-trunk.html#user-panel-assign-trunk) **Create a SIP Trunk** Create and configure SIP trunks for inbound calls, set transport protocols, authentication, media options, and more. [SIP Trunk](creating-a-new-sip-trunk.html#user-panel-sipin-trunk) On this page