Extensions

Extensions are the foundation of your PBX system. They represent numbered endpoints that callers can reach directly or through routing configurations.

What Is an Extension

An extension is a numbered endpoint (typically 3-5 digits) that represents a phone destination within your organization. Extensions can be assigned to users, forwarded to external numbers, or connected to automated services.

Extension Types

OPBX supports multiple extension types for different use cases:

Type	Description	Configuration
User	SIP phone extension for a person	Assigned to a user, auto-generated SIP password
Conference	Routes to a conference room	Select conference room
Ring Group	Routes to a ring group	Select ring group
IVR	Routes to an IVR menu	Select IVR menu
AI Assistant	Routes to an AI provider	Select AI assistant
Forward	Forwards to external number	Enter phone number
AI Load Balancer	Routes to AI load balancer	Select load balancer
Custom Logic	Custom application routing	Container app/block name

Creating an Extension

To create a new extension:

1. Navigate to the Extensions page
2. Click Create Extension
3. Enter an extension number (3-5 digits, unique within your organization)
4. Select the extension type
5. Configure type-specific settings
6. Save the extension

warning

Extension numbers cannot be changed after creation. If you need a different number, delete the extension and create a new one.

User Extensions

User extensions are the most common type. They connect to SIP phones or softphones.

SIP Credentials

When you create a User extension, OPBX auto-generates a SIP password. View the credentials on the extension detail page:

• SIP Username: The extension number
• SIP Password: Auto-generated secure password
• SIP Server: Provided by your administrator

Resetting SIP Password

If a user loses their SIP password or suspects compromise:

1. Open the extension details
2. Click Reset Password
3. The new password displays immediately
4. Update the SIP phone configuration

note

Resetting the SIP password disconnects any active registrations. The SIP phone must re-register with the new credentials.

Voicemail

Enable voicemail on User extensions to capture messages when the user is unavailable:

• Toggle voicemail on/off in extension settings
• Voicemail notifications sent to the assigned user's email
• Access voicemail through the SIP phone or web portal

Cloudonix Synchronization

User extensions sync to Cloudonix as SIP subscribers. This enables the Cloudonix platform to route calls to your SIP phones.

Manual Sync

Click the Sync button on the Extensions page to trigger synchronization. This is useful when:

• A new extension is not registering
• Credentials were reset
• Changes appear not to be taking effect

Bidirectional Sync

Synchronization works in both directions:

• Local to Cloudonix: New extensions and credential changes push to Cloudonix
• Cloudonix to Local: Existing subscribers import as extensions

tip

Run a sync after bulk imports or when migrating from another system.

Extension Status

Extensions have one of two statuses:

Status	Behavior
Active	Receives calls normally
Inactive	Calls rejected or routed to voicemail

Set an extension to Inactive when:

• The user is on extended leave
• The extension is being repurposed
• You want to block calls without deleting the extension

Extension Best Practices

Numbering Plan

Develop a consistent numbering plan for your organization:

• Reserve 3-digit extensions for departments (100-199 for sales, 200-299 for support)
• Use 4-digit extensions for individual users
• Avoid numbers that conflict with feature codes

Assignment

• Assign extensions to specific users when possible
• Use descriptive labels for non-user extensions (conference rooms, ring groups)
• Document forwarding rules for Forward-type extensions

Security

• Reset SIP passwords periodically
• Disable extensions instead of leaving them active but unused
• Monitor registration logs for unauthorized devices