# Create a PSTN trunk

Create an inbound PSTN trunk to forward calls received on DIDWW DID numbers
to a telephone number on the Public Switched Telephone Network (PSTN), such
as a landline or mobile number. Configure the destination, check its
per-minute rate, and optionally set capacity and ringing timeout, filter
callers with a Number List, or add the trunk to a Trunk Group for failover or
load balancing.

For how DIDWW forwards calls to a PSTN destination, see [PSTN trunks](../index.html).

Note

Calls forwarded through a PSTN trunk are charged per minute. The rate and
destination availability depend on the **PSTN Phone Number**. See
[DIDWW pricelists](../../../../phone-numbers/buy-numbers/download-pricelists.html#services-coverage-pricing-access-pricelists) for
current pricing.

## Before you begin

- An active DIDWW account is required. [Sign in to DIDWW](https://my.didww.com/users/sign_in) or [Create DIDWW account](https://my.didww.com/users/sign_up#/users/sign_up).

## Step 1: Open the creation form

1. In the DIDWW User Panel, open **Voice**.
2. Select **Inbound Trunks**.
3. Click **Create New**.
4. Select **PSTN Trunk**.

[![Create New menu on the Inbound Trunks page with PSTN Trunk available](../../../../_images/fig11.webp)](../../../../_images/fig11.webp)


**Fig. 1.** Select PSTN Trunk

## Step 2: Configure the General settings

On the **General** tab, enter the required trunk name and destination, then
review the optional capacity and ringing timeout settings.

1. Enter a unique **Name** to identify the trunk in the DIDWW User Panel.
2. In **PSTN Phone Number**, enter the destination in E.164 format using the
   country code, area code, and subscriber number without `+`. For example,
   `12065550100`. This is the number that receives forwarded calls, not the
   DID number that callers dial.
3. Click **Check Rate** and review the displayed per-minute rate. If **Rate
   is unavailable** is displayed, enter a different destination and click
   **Check Rate** again.

Field definitions, available values, and constraints are listed in
[General settings](../pstn-trunk-settings-reference.html#inbound-pstn-trunks-settings-general).

[![PSTN trunk name and destination configured with the per-minute rate displayed](../../../../_images/quick_configuration.png)](../../../../_images/quick_configuration.png)


**Fig. 2.** Configure the PSTN destination

4. Optionally set **Capacity Limit** to restrict the number of simultaneous
   calls delivered through this trunk. The default value is **Unlimited**. In
   a Trunk Group, DIDWW tries another trunk when the limit is reached.
5. Optionally set **Ringing Timeout** to limit how long DIDWW waits for the
   destination to answer after receiving an `18x` response.

[![General tab with PSTN destination, capacity limit, and ringing timeout settings](../../../../_images/general1.png)](../../../../_images/general1.png)


**Fig. 3.** Configure capacity and ringing timeout

## Step 3: Configure optional settings

Configure these tabs only if you need caller ID filtering or Trunk Group
membership. Otherwise, skip this step and create the trunk with the
**General** settings only.

### Number Translations

Filter forwarded calls by caller ID with a Number List. The list matches the
caller's number, not the **PSTN Phone Number** configured as the forwarding
destination.

Field definitions, available values, and constraints are listed in
[Number Translations](../pstn-trunk-settings-reference.html#inbound-pstn-trunks-settings-number-translations).
For how Number Lists allow or reject calls, see [Number Lists](../../number-lists/index.html).

[![Number Translations tab with the CLI Number List field](../../../../_images/number_translations.png)](../../../../_images/number_translations.png)


**Fig. 4.** Assign a Number List

### Trunk Group

Add the trunk to a Trunk Group and set how it is selected within the group.
Use this tab only when the trunk will participate in failover or load
balancing. A trunk can belong to only one Trunk Group.

Field definitions, available values, and constraints are listed in
[Trunk Group settings](../pstn-trunk-settings-reference.html#inbound-pstn-trunks-settings-trunk-group).

For how Trunk Groups work, see [Trunk Groups](../../trunk-groups/index.html).
To create a group, see [Create a Trunk Group](../../trunk-groups/how-to-guides/create-trunk-group.html). For how
priority and
weight work, see [Service failover and load
balancing](../../sip-trunks/call-handling-and-delivery/service-failover-and-load-balancing.html#inbound-sip-failover-load-balancing).

[![Trunk Group tab with trunk group, priority, and weight settings](../../../../_images/trunk_group.png)](../../../../_images/trunk_group.png)


**Fig. 5.** Configure the Trunk Group settings

## Step 4: Create the trunk

1. Review the trunk configuration and the destination's per-minute rate.
2. Click **Create** to save the trunk.

The new trunk appears on the **Trunks** tab under **Voice > Inbound Trunks**.
Creating the trunk does not assign it to a DID number.

[![Create button highlighted on the Create Inbound PSTN Trunk form](../../../../_images/create1.webp)](../../../../_images/create1.webp)


**Fig. 6.** Create the trunk

## Next steps

- [Assign the trunk or its Trunk Group to one or more DID numbers](../../../../phone-numbers/my-numbers/how-to-guides/assign-voice-trunk.html#user-panel-assign-trunk) before receiving calls. Each DID number must have
  sufficient [Capacity](../../../../phone-numbers/capacity/how-capacity-works.html).
- Place a test call to an assigned DID number, then review [Inbound Call
  Logs](../../../../logs-analytics/call-logs/inbound-logs.html#inbound-cdr-logs) if the call does not reach the PSTN
destination.

## Related resources

- [PSTN trunk settings reference](../pstn-trunk-settings-reference.html) -
  Look up field definitions, defaults, dependencies, and limits.
- [PSTN trunks](../index.html) - Understand PSTN forwarding, destination
  availability, and per-minute billing.
- [Assign a voice trunk](../../../../phone-numbers/my-numbers/how-to-guides/assign-voice-trunk.html#user-panel-assign-trunk) - Assign the trunk to
  one or more DID numbers.
- [Manage PSTN trunks](manage-pstn-trunks.html) - View, edit, or delete an
  existing PSTN trunk.

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