Remote Viewer timeout on private/corporate network despite firewall ports open: enable Accessibility or deploy Supervisor Plugin

Android

If you're unable to establish a Remote Control session to managed devices on your corporate network—even after opening firewall ports—you may need to enable Accessibility permissions or deploy the Esper Supervisor Plugin. This article walks you through both solutions.

Before you begin

Remote Viewer timeouts on private or corporate networks typically occur when:

• Your device is connected to a restricted network with a stateful firewall or proxy
• Deep-packet inspection, SSL interception, or other network security controls are interfering with WebRTC/relay traffic
• Esper Management Service lacks the necessary device-level permissions

Remote Control works fine on public internet connections but fails exclusively on your corporate network—this points to a combination of network policies and missing device permissions.

Step 1: Enable Accessibility permissions

Esper Management Service requires Accessibility permissions to establish Remote Control sessions.

1. On the managed device, open Settings → Accessibility.
2. Locate Esper Management Service (it may appear as "Esper Agent" depending on your setup).
3. Toggle it ON.
4. In the Esper Console, go to Devices & Groups → [Device Name] → Remote Viewer and start a new session.

If the session connects, Accessibility was the missing piece. If the timeout persists on your corporate network, continue to Step 2.

Step 2: Deploy the Esper Supervisor Plugin

If Accessibility is enabled but Remote Control still times out on your corporate network, the Supervisor Plugin provides system-level control permissions without requiring manual Accessibility configuration.

1. Confirm your exact device model (for example, HP Engage One Pro AIO System).
2. Contact Esper Support with your device model. Esper will provide an unsigned Supervisor Plugin APK.
3. Send the unsigned APK to your device's OEM (Original Equipment Manufacturer) to be signed with their platform keys.
4. Return the signed APK to Esper Support.
5. Esper uploads the signed plugin to your tenant—it deploys automatically to all devices of that model.
6. Retry a Remote Control session on your corporate network.

Step 3: Verify firewall and network configuration

If both Accessibility and the Supervisor Plugin are in place but Remote Control still times out, verify your network setup:

1. Confirm all ports listed in the Esper Firewall Requirements are open, including UDP ranges for WebRTC and TURN.
2. Ask your network or security team to check for:
   • SSL inspection or proxy interception
   • Connection-state tracking that terminates long-lived or UDP-based sessions
   • Specific hostnames or IPs that are timing out (obtain this via packet capture or firewall logs)
3. Arrange a call with your security team to review the exact traffic path and identify any remaining blocks.

Still need help?

If Remote Viewer continues to time out after enabling Accessibility, deploying the Supervisor Plugin, and verifying your firewall configuration, contact Esper Support. include:

• Device logs from a failed Remote Control attempt
• Firewall rule export showing open ports and protocols
• Your network topology (proxy type, SSL inspection status, TURN relay reachability)
• Confirmation of whether Remote View (screen-only, no control) works while Remote Control fails