Manage Outbound Trunks

DIDWW outbound trunks enable routing of voice traffic to external destinations via DIDWW termination routes. This section covers the steps how to create and configure outbound trunks, including authentication, media settings, and termination routes for efficient call management.


Create Outbound Trunk

To create an outbound trunk, go to the Voice section, select Outbound Trunks, and click Create new (Fig. 1).

Creating a new Outbound Trunk

Fig. 1 Creating a new Outbound Trunk

On the Create outbound trunk page, enter the following information (see Fig. 2):

  • Friendly Name

  • Allowed SIP IP addresses

Outbound Trunks settings

Fig. 2 Outbound Trunks settings

In addition to the basic settings, advanced authentication options are available below. These settings can be left unchanged unless specific configuration is required.

Authentication

The Authentication section allows you to configure how your system authorizes the outbound trunk.

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Fig. 3 Authentication section with Credentials & IP-Based option.

The following authentication methods are available:

1. Credentials & IP-Based

This method is selected by default when creating an outbound trunk. It uses trunk credentials and allowed IP addresses to authenticate outbound calls (Fig. 3).

  • Allowed IP addresses - your system’s IP address from which calls are sent to DIDWW.

  • Allowed RTP IP addresses - your RTP addresses from which audio packets will be relayed to DIDWW.

Note

  • The maximum number of allowed SIP and RTP IPs and subnets is 60.

  • By default, a trunk cannot be created without adding at least one Allowed SIP IP address. To allow any IP address (not recommended for security reasons), you can add 0.0.0.0/0.

2. Twilio Account SID

This method enables trunk creation for Twilio integration (Fig. 4). For more details, see the Twilio Integration Guide .

  • Accound SID - a 34 character string that uniquely identifies Twilio account.


Media

The Media section (Fig. 5) provides options to configure how media (audio packets) is handled for outbound trunks. These settings ensure compatibility and enhance security during call setup and transmission.

Media Settings

Fig. 5 Media Settings

1. Media Settings

  • Force Symmetric RTP: When enabled, the trunk operates in Symmetric RTP/COMEDIA mode.

  • RTP Ping: When enabled, RTP ping is used to establish the connection for a call.

2. Media Encryption

The Media Encryption Mode dropdown allows you to select the type of encryption for securing media (audio packets). The following options are available:

  • Disabled: Media encryption is turned off.

  • SRTP SDES: Secure Real-Time Transport Protocol (SRTP) encryption using Session Description Protocol Security Descriptions (SDES).

  • SRTP DTLS: SRTP encryption using Datagram Transport Layer Security (DTLS).

  • ZRTP: SRTP encryption using ZRTP (key exchange protocol for securing VoIP calls).

Note

Media encryption is not enabled by default. To enable this feature, contact sales@didww.com .

Termination

The Termination section allows you to configure Limits and Notifications for outbound trunk usage, as well as manage CLI Settings and Destination Dialing Settings.

1. Limits and Notification

  • 24-hour limit (USD): Sets the maximum amount of funds allowed per trunk over a rolling 24-hour period. If this limit is reached, traffic on the trunk is blocked, and active calls will be disconnected within a few minutes.

  • Capacity limit: Specifies the maximum number of simultaneous calls allowed per trunk.

  • Voice OUT Trunk usage limit notification: Sends an email notification when 80% of the 24-hour limit is reached. Notifications are sent once every 12 hours.

Note

The default 24-hour limit is $3000. The minimum limit is $50, and the maximum limit is $10000.

2. CLI Settings

On CLI Mismatch

A CLI mismatch occurs when numbers from other providers are used as the CLI or when the CLI does not match any numbers acquired via DIDWW. In this situation, you can choose one of the following options:

  • Send Original CLI: DIDWW will pass the “From” header value from your system to the PSTN gateway without modification.

  • Reject Call: DIDWW will reject the call if the “From” header value does not match any DID numbers allowed in the CLI Settings list.

Allow any DID(s) as CLI for Voice OUT

When Allow any DID(s) for Voice OUT toggle is enabled, all supported numbers are automatically used as the CLI by default.

Allow specific DIDs as CLI for Voice OUT

When Allow any DID(s) for Voice OUT toggle is disabled, only numbers added to the Allowed CLI(s) list can be used as the CLI.

Note

The Available CLI(s) list displays only DID numbers that support the Voice OUT feature with local termination. DIDs with the Voice OUT global routes feature are not included in this list.

Tip

To define allowed CLIs:

  1. Use the filters to narrow down the list of Available CLI(s).

  2. Select the desired numbers from the Available CLI(s) list.

  3. Click the > button to add them to the Allowed CLI(s) list.

  4. If you want to allow all listed CLIs, click Add all to move all numbers to the Allowed CLI(s) list.

  5. To remove a number from the Allowed CLI(s) list, select the number and click the < button.

3. Destination Dialing Settings

The Destination Dialing Settings section allows you to restrict calls to unwanted destinations using the following methods:

Allow All

This method allows calls to all destinations, except those specified in the listed prefixes.

For example, the following configuration allows calls to all destinations except:

  • London, UK (4420)

  • Ireland (353)

  • New York, US (1212)

Reject All

This method rejects calls to all destinations, except those specified in the listed prefixes.

For example, the following configuration rejects calls to all destinations except:

  • Bogota, Colombia (571)

  • Lancaster, US (1740)

  • Mobile, Denmark (4592)


Emergency Calling

To use the emergency calling service with an outbound trunk, you must first have a DID number that supports emergency services and has emergency service activated.

Follow the steps below to complete the setup:

1. Create & activate emergency calling service

Follow this guide to check your DID eligibility and activate emergency services.

Create Emergency Calling Service
2. Configure outbound trunk for emergency calling

Use this guide to enable emergency calling on your outbound trunk after activation.

Configure Emergency Calling Service for Outbound Trunk

View Outbound Trunk Credentials

If your outbound trunk uses the Credentials & IP-based authentication method, you can view its credentials by selecting the key icon in the Credentials column on the Outbound Trunks page (see Fig. 12).

Accessing SIP credentials

Fig. 12 Accessing SIP credentials.

The SIP credentials dialog provides the following details (Fig. 13):

  • Auth type – The authentication method used for the trunk (for example, Credentials & IP-based).

  • Username – The unique username assigned to the SIP trunk.

  • Password – The password for the SIP trunk. You can select the eye icon to view the password or the regenerate icon to generate a new one.

  • Host(s) – Hostnames of the SIP servers available for the trunk.

  • Allowed SIP IPs – IP addresses that are authorized to send traffic to the trunk.

  • Allowed Voice OUT CLI(s) – Caller IDs permitted for outbound voice traffic.

  • Emergency calling CLI(s) – Caller IDs that can be used for emergency calling.

SIP credentials details

Fig. 13 SIP credentials details


Edit Outbound Trunks

To edit an existing outbound trunk, follow these steps:

  1. Navigate to the Voice section in the left-hand menu.

  2. Select Outbound Trunks from the submenu.

  3. Locate the trunk that you want to edit and click the actions button.

  4. Click Edit.

Actions Button.

Fig. 14. Actions Button.

  1. In the Edit Outbound Trunk, perform the changes and click Submit to save the changes.

Edit Outbound Trunk.

Fig. 15. Edit Outbound Trunk.

Delete Outbound Trunks

You can either delete a single outbound trunk or delete multiple outbound trunks using batch actions.

Delete a Single Outbound Trunk

To delete an existing outbound trunk, follow these steps:

  1. Navigate to the Voice section in the left-hand menu.

  2. Select Outbound Trunks from the submenu.

  3. Locate the trunk that you want to delete and click the actions button.

  4. Click Delete.

Actions Button.

Fig. 16. Actions Button.

  1. In the pop-up Delete Trunk(s) window, click Delete to confirm the trunk deletion.

Delete a Single Trunk.

Fig. 17. Delete a Single Trunk.

Delete Multiple Outbound Trunks

To delete multiple outbound trunks, follow these steps:

  1. Navigate to the Voice section in the left-hand menu.

  2. Select Outbound Trunks from the submenu.

  3. Locate the trunks that you want to delete and check them.

  4. Click on the Batch Actions button and select Delete.

Batch Actions Button.

Fig. 18. Batch Actions Button.

  1. In the pop-up Delete Trunk(s) window, click Delete to confirm the trunk deletion.

Delete Multiple Trunks.

Fig. 19. Delete Multiple Trunks.


Additional Information

Outbound Dialing

Learn about configuring outbound dialing, including number format, local routes, and short numbers.

Outbound Dialing
Termination Services Technical Data

Explore technical specifications and detailed information on termination services, including supported network protocols, signaling endpoints, encryption options, codecs, and other SIP protocol details.

SIP Protocol Details