Listeners

A Listener defines the port on which the USP Server accepts inbound connections and specifies the Outbound Node that connects to the internal target. It primarily specifies the following:

• The port on which the USP Server listens for external incoming connections.
• The Route that links Inbound Nodes to Outbound Nodes, determining where incoming connections are forwarded.
• The Default Outbound Node, which indicates which Outbound Node the Listener will use when handling connections.

By default, the USP Server listens exclusively for USP Manager connections on a predefined port. Once a configuration that includes one or more Listener definitions is deployed, the USP Server instance begins accepting inbound connections based on the configuration of each Listener.

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To create a Listener, you must first add a Route with at least one Outbound Node.

Before You Begin

Port

The Port specifies the network port on which the Listener accepts incoming connections. It must be a valid and available port on the USP Server host. Ensure that the selected port is open, not blocked by a firewall, and not already in use by another service.

Route

The Route associates the Listener with a specific Route configuration. A Route defines how inbound connections are forwarded to internal targets. It determines the target address, authentication mechanisms, and protocol-specific forwarding behavior.

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For further details, refer to Routes.

Default Outbound Node

The Default Outbound Node specifies the internal target to which all authorized incoming connections are forwarded.

Listener Administration via USP Admin UI

Adding a Listener

To add a Listener, follow these steps:

1. From the Sidebar, click Configuration > Listeners.
2. Click Add Listeners.
3. Complete the details for the new Listener using the Field Descriptions table as a guide.
4. Click Save.

Field Descriptions

Name	Description	Specifications	Required
Name	The name of the Listener.	Must be unique.	Yes
Description	The description of the Listener.		No
Port	The port of the Listener.	Must be within 1 and 65535.	Yes
Route	The Route associated with the Listener.	Must reference an already-created Route.	Yes
Default Outbound Node	The Outbound Node to which the Listener forwards incoming connections.		Yes

Editing a Listener

To edit a Listener, follow these steps:

1. From the Sidebar, click Configuration > Listeners.
2. Click the Name of the Listener you want to edit.
3. Click Edit.
4. Edit the Listener details using the Field Descriptions table as a guide.
5. Click Save.

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If you modify a Listener that is currently associated with a USP Server instance, the updated configuration must be manually applied. To do this, follow these steps:

1. Navigate to Monitoring > Status.
2. Click the Name of the associated server.
3. Go to the Configuration tab.
4. Review the pending changes in the Candidate Configuration - Preview section.
5. If the changes are correct, click Push Configuration.

Additionally, if you edit the Listener's port, you also need to restart the Listener. To do this, follow these steps:

1. Go to the Live Listeners tab.
2. Click the [ ··· ] button.
3. Click the Stop Listener button.
4. Click the [ ··· ] button again.
5. Click Start Listener.

The changes do not take effect on the server until these steps are completed.

Listener details include all parameters given in the Field Descriptions table above, plus the following read-only metadata:

Listener Metadata

Name	Description
ID	Universally Unique Identifier of this Listener.
Routing Method	The routing method that the Listener uses. The only possible value is standard.
Created At	Date and time this Listener was created.
Updated At	Date and time this Listener was last updated.

Deleting a Listener

To delete a Listener, follow these steps:

1. From the Sidebar, click Configuration > Listeners.
2. Click the Name of the Listener you want to delete.
3. Click the Delete button above the Listener details.
4. You will be asked to confirm the deletion. Click Delete.

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To delete a Listener, you must first delete its associated Deployment. Additionally, the USP Server instance configuration must be manually updated. To do this, follow these steps:

1. Navigate to Monitoring > Status.
2. Click on the associated server.
3. Go to the Configuration tab.
4. Click Push Configuration.

The changes do not take effect on the server until these steps are completed.

Managing Listeners

After deploying a Listener to a USP Server instance (by creating a Deployment and pushing the configuration), you can monitor, start, and stop the listener from the Status dashboard. See Live Listeners Tab​ for more information.