UniFi UMR MODE: LTE Passthrough

Key Points

• It seems likely that LTE Passthrough on Ubiquiti UMR devices allows the router to act as a bridge, passing the LTE connection directly to another device connected via LAN, disabling its own routing and firewall functions.
• Research suggests this feature enables the connected device to receive the public IP from the LTE network, useful for using another router for network management.
• The evidence leans toward LTE Passthrough being added via a firmware update, configurable through the device's GUI or Mobility Cloud, though exact setup steps may vary.

What is LTE Passthrough?

LTE Passthrough is a feature on Ubiquiti's UMR series that allows the device to act as a bridge for the LTE connection. Instead of routing traffic itself, the UMR passes the LTE connection directly to another device connected to its LAN port, such as another router. This means the connected device will receive the public IP address from the LTE network and handle all networking tasks, like firewall and NAT, independently.

How Does It Work on the Device?

When LTE Passthrough is enabled, the UMR disables its own routing and firewall functions, effectively acting as a transparent bridge. This ensures there is no additional NAT or firewall interference from the UMR, providing a direct path for data between the LTE network and the connected device. This mode is particularly useful for setups where you want to use your own router for network management while leveraging the UMR for LTE connectivity.

Unexpected Detail

An interesting aspect is that LTE Passthrough was reportedly added via a firmware update, and its availability might depend on the LTE provider supporting this mode, which could affect compatibility in some regions.

Survey Note: Detailed Analysis of LTE Passthrough on Ubiquiti UMR Devices

This section provides a comprehensive exploration of LTE Passthrough on Ubiquiti's UMR series, including its functionality, setup, and implications, based on available information from technical specifications, user reports, and community discussions. The analysis aims to cover all relevant details for both technical and non-technical audiences, ensuring a thorough understanding of the feature.

Overview of LTE Passthrough

LTE Passthrough is a networking feature that allows a device, in this case, Ubiquiti's UMR (UniFi Mobile Router) series, to act as a bridge for its LTE connection. In this mode, the UMR does not perform routing or firewall functions; instead, it passes the LTE connection directly to another device connected to its LAN port. This enables the connected device, typically another router or network appliance, to receive the public IP address from the LTE network and handle all subsequent networking tasks, such as NAT, firewall, and routing.

This feature is particularly useful in scenarios where users prefer to use their existing network infrastructure for management while utilizing the UMR solely for providing LTE connectivity. For example, it can be used as a WAN backup on a UniFi Dream Machine (UDM), ensuring seamless integration without double NAT issues.

Functionality and Operation

When LTE Passthrough is enabled on the UMR, the device essentially becomes a transparent bridge for the LTE connection. This means:

• The UMR does not perform Network Address Translation (NAT), which is typical in router mode, where it would assign private IP addresses to connected devices.
• The firewall functions are disabled, as noted in user reports, ensuring no filtering or blocking occurs at the UMR level.
• The device connected to the UMR's LAN port, such as a router, receives the public IP address directly from the LTE network provider, allowing it to manage the network independently.

This mode is analogous to bridge mode in other networking devices, where the primary device acts as a layer 2 bridge, passing data without modifying it, rather than acting as a layer 3 router. This setup is beneficial for avoiding double NAT scenarios, which can cause issues with certain applications, such as VoIP or gaming, that require direct public IP access.

Setup and Configuration

Based on community reports, LTE Passthrough was introduced via a firmware update for the UMR series, particularly noted for the UMR-Industrial model. To set up LTE Passthrough, users typically need to:

1. Ensure the device is running the latest firmware, as this feature may not be available in older versions.
2. Access the device's graphical user interface (GUI) locally or through the Mobility Cloud platform, which requires a subscription for advanced configurations.
3. Navigate to the Settings tab within the GUI and look for the option to change the mode to "LTE Passthrough."
4. Enable the mode, which reportedly disables the firewall, and ensure the connected device is configured to handle the LTE connection, such as setting it to use DHCP for IPv4 connection type.

However, exact steps may vary depending on the model (e.g., UMR-Industrial, UMR-US, UMR-Ultra-US) and firmware version. Official documentation from Ubiquiti, such as user manuals or tech specs, does not explicitly detail LTE Passthrough, suggesting users rely on community forums or release notes for guidance. For instance, a Reddit post from August 26, 2024, mentions that the UMR-I received an update allowing local login to enable this mode, highlighting its utility as a WAN backup on a UDM, provided the LTE provider supports passthrough.

Compatibility and Limitations

An important consideration is that LTE Passthrough's functionality may depend on the LTE provider. Some providers might not support passthrough modes, which could limit its effectiveness in certain regions or networks. This dependency is noted in user discussions, where it's mentioned that the feature works "as long as the LTE provider supports LTE Passthrough."

Additionally, the feature's availability and configuration options might be limited without a Mobility Cloud subscription, which costs $2 per month per device. Basic management, such as WiFi configuration, is available locally via the UniFi mobile app, but advanced settings like LTE Passthrough may require the cloud platform, potentially adding to operational costs.

Use Cases and Benefits

LTE Passthrough is particularly advantageous in the following scenarios:

• WAN Backup: Users can set up the UMR as a backup internet connection for their primary router, ensuring continuity during WAN outages without double NAT. For example, it can be used with a UniFi Dream Machine (UDM) as mentioned in community posts.
• Fleet Management: Given the UMR's marketing towards mobile operations, LTE Passthrough can simplify network management in vehicles or remote sites by allowing a central router to handle all traffic.
• Avoiding Double NAT: By passing the public IP directly to another device, users can avoid the performance and compatibility issues associated with double NAT, such as difficulties with port forwarding or VPN setups.

The feature enhances flexibility, especially for users with existing network infrastructure, by integrating LTE connectivity without requiring the UMR to act as the primary router.

Technical Specifications and Comparison

To provide context, here's a table comparing key aspects of the UMR series, based on available specifications, which may influence LTE Passthrough functionality:

This table highlights that while all models support LTE Cat 4, differences in ports, power, and ruggedness might affect their suitability for LTE Passthrough setups, especially in industrial or mobile environments.

Community Insights and Unexpected Details

Community discussions, particularly on Reddit, reveal that LTE Passthrough was not initially available but added via updates, which is an unexpected detail given its importance for advanced networking setups. For instance, a post from August 26, 2024, notes that the UMR-Industrial's update enabled this mode, making it a viable WAN backup option. Another unexpected aspect is the dependency on LTE providers, which could limit its universal applicability, as not all providers support passthrough modes.

Users also report challenges, such as limited GUI settings without Mobility Cloud, suggesting that advanced configurations might require additional investment. This aligns with the broader trend of Ubiquiti offering cloud-based management for enhanced features, which could be a consideration for cost-sensitive users.

Conclusion

LTE Passthrough on Ubiquiti's UMR series is a valuable feature for bridging LTE connectivity to another device, enhancing flexibility in network management. It works by disabling the UMR's routing and firewall functions, passing the LTE connection directly to the connected device, which then handles all networking tasks. While setup details may vary and depend on firmware updates and provider support, it offers significant benefits for WAN backup and avoiding double NAT. Users should consult community forums, such as Reddit discussions, for practical setup tips and consider the Mobility Cloud for advanced configurations.

Key Citations

• Reddit discussion on UMR-Industrial update
• HostiFi blog on UniFi Mobile Router review
• Ubiquiti Help Center comparing U-LTE and UMR devices
• wifi-u blog on UMR in-depth review
• UBIQUITI UMR-US Mobile Router User Manual
• UniFi Mobile Router UMR Setup Guide Adopt
• UniFi Mobile Router Industrial Tech Specs
• UBIQUITI UMR-Industrial Installation Guide
• UBIQUITI UMR-US UniFi Mobile Router Installation Guide